Domain Names

A web hosting service is a type of Internet hosting service that allows individuals and organizations to provide their own website accessible via the World Wide Web. Web hosts are companies that provide space on a server they own for use by their clients as well as providing Internet connectivity, typically in a data center. Web hosts can also provide data center space and connectivity to the Internet for servers they do not own to be located in their data center, called colocation.

[edit] Service scope

The scope of hosting services varies widely. The most basic is web page and small-scale file hosting, where files can be uploaded via File Transfer Protocol (FTP) or a Web interface. The files are usually delivered to the Web "as is" or with little processing. Many Internet service providers (ISPs) offer this service free to their subscribers. People can also obtain Web page hosting from other, alternative service providers. Personal web site hosting is typically free, advertisement-sponsored, or cheap. Business web site hosting often has a higher expense.

Single page hosting is generally sufficient only for personal web pages. A complex site calls for a more comprehensive package that provides database support and application development platforms (e.g. PHP, Java, Ruby on Rails, ColdFusion, and ASP.NET). These facilities allow the customers to write or install scripts for applications like forums and content management. For e-commerce, SSL is also highly recommended.

The host may also provide an interface or control panel for managing the Web server and installing scripts as well as other services like e-mail. Some hosts specialize in certain software or services (e.g. e-commerce). They are commonly used by larger companies to outsource network infrastructure to a hosting company.

[edit] Hosting reliability and uptime

Multiple racks of servers.

Hosting uptime refers to the percentage of time the host is accessible via the internet. Many providers state that they aim for a 99.9% uptime, but there may be server restarts and planned (or unplanned) maintenance in any hosting environment.

A common claim from the popular hosting providers is '99% or 99.9% server uptime' but this often refers only to a server being powered on and doesn't account for network downtime. Real downtime can potentially be larger than the percentage guaranteed by the provider. Many providers tie uptime and accessibility into their own service level agreement (SLA). SLAs sometimes include refunds or reduced costs if performance goals are not met.

[edit] Types of hosting

A typical server "rack," commonly seen in colocation centres.

Internet hosting services can run Web servers; see Internet hosting services.

Hosting services limited to the Web:

• Free web hosting service: is free, (sometimes) advertisement-supported web hosting, and is often limited when compared to paid hosting. [1]

• Shared web hosting service: one's Web site is placed on the same server as many other sites, ranging from a few to hundreds or thousands. Typically, all domains may share a common pool of server resources, such as RAM and the CPU. The features available with this type of service can be quite extensive. A shared website may be hosted with a reseller.
• Reseller web hosting: allows clients to become web hosts themselves. Resellers could function, for individual domains, under any combination of these listed types of hosting, depending on who they are affiliated with as a provider. Resellers' accounts may vary tremendously in size: they may have their own virtual dedicated server to a colocated server. Many resellers provide a nearly identical service to their provider's shared hosting plan and provide the technical support themselves.
• Virtual Dedicated Server: dividing a server into virtual servers, where each user feels like they're on their own dedicated server, but they're actually sharing a server with many other users. The users may have root access to their own virtual space. This is also known as a virtual private server or VPS. Customers are sometimes responsible for patching and maintaining the server.
• Dedicated hosting service: the user gets his or her own Web server and gains full control over it (root access for Linux/administrator access for Windows); however, the user typically does not own the server. Another type of Dedicated hosting is Self-Managed or Unmanaged. This is usually the least expensive for Dedicated plans. The user has full administrative access to the box, which means the client is responsible for the security and maintenance of his own dedicated box.
• Managed hosting service: the user gets his or her own Web server but is not allowed full control over it (root access for Linux/administrator access for Windows); however, they are allowed to manage their data via FTP or other remote management tools. The user is disallowed full control so that the provider can guarantee quality of service by not allowing the user to modify the server or potentially create configuration problems. The user typically does not own the server. The server is leased to the client.
• Colocation web hosting service: similar to the dedicated web hosting service, but the user owns the colo server; the hosting company provides physical space that the server takes up and takes care of the server. This is the most powerful and expensive type of the web hosting service. In most cases, the colocation provider may provide little to no support directly for their client's machine, providing only the electrical, Internet access, and storage facilities for the server. In most cases for colo, the client would have his own administrator visit the data center on site to do any hardware upgrades or changes.
• Clustered hosting: having multiple servers hosting the same content for better resource utilization. Clustered Servers are a perfect solution for high-availability dedicated hosting, or creating a scalable web hosting solution.
• Grid hosting : this form of distributed hosting is when a server cluster acts like a grid and is composed of multiple nodes.
• Home server: usually a single machine placed in a private residence can be used to host one or more web sites from a usually consumer-grade broadband connection. These can be purpose-built machines or more commonly old PCs. Some ISPs actively attempt to block home servers by disallowing incoming requests to TCP port 80 of the user's connection and by refusing to provide static IP addresses. A common way to attain a reliable DNS hostname is by creating an account with a dynamic DNS service. A dynamic DNS service will automatically change the IP address that a URL points to when the IP address changes.

  Some specific types of hosting provided by web host service providers:

• File hosting service: hosts files, not web pages
• Image hosting service
• Video hosting service
• Blog hosting service
• One-click hosting
• Shopping cart software

[edit] Obtaining hosting

Web hosting is often provided as part of a general Internet access plan; there are many free and paid providers offering these services.

A customer needs to evaluate the requirements of the application to choose what kind of hosting to use. Such considerations include database server software, scripting software, and operating system. Most hosting providers provide Linux-based web hosting which offers a wide range of different software. A typical configuration for a Linux server is the LAMP platform: Linux, Apache, MySQL, and PHP/Perl/Python. The webhosting client may want to have other services, such as email for their business domain, databases or multi-media services for streaming media. A customer may also choose Windows as the hosting platform. The customer still can choose from PHP, Perl, and Python but may also use ASP .Net or Classic ASP.

Web hosting packages often include a Web Content Management System, so the end-user doesn't have to worry about the more technical aspects. These Web Content Management systems are great for the average user, but for those who want more control over their website design, this feature may not be adequate.

Most modern desktop operating systems (Windows, Linux, Mac OS X) are also capable of running web server software, and thus can be used to host basic websites.

One may also search the Internet to find active webhosting message boards and forums that may provide feedback on what type of webhosting company may suit his/her needs. However some of these message boards and forums will require not only registration, but a paid subscription to be able to access the sections and sub forums with such information.

[edit] See also

• Overselling
• Shared web hosting service
• Dedicated hosting service

[edit] References

1. ^ What types of webhosting are there

A virtual private server (VPS, also referred to as Virtual Dedicated Server or VDS) is a method of partitioning a physical server computer into multiple servers such that each has the appearance and capabilities of running on its own dedicated machine. Each virtual server can run its own full-fledged operating system, and each server can be independently rebooted.

The practice of partitioning a single server so that it appears as multiple servers has long been common practice in mainframe computers, but has seen a resurgence lately with the development of virtualization software and technologies for other architectures.

[edit] Overview

Please help improve this section by expanding it. Further information might be found on the talk page. (June 2008)

The physical server boots normally. It then runs a program that boots each virtual server within a virtualization environment (similar to an emulator). The virtual servers have no direct access to hardware and are usually booted from a disk image.

There are two kinds of virtualizations: software based and hardware based. In a software based virtualization environment, the virtual machines share the same kernel and actually require the main node's resources. This kind of virtualization normally has many benefits in a web hosting environment because of quota incrementing and decrementing in real time with no need to restart the node. The main examples are Xen, Virtuozzo, Vserver, and OpenVZ (which is the open source and development version of Parallels Virtuozzo Containers).

In a hardware based virtualization, the virtualization mechanism partitions the real hardware resources. In typical implementations, no burst and/or realtime quota modification is possible; the limits are hard and can only be modified by restarting a virtual machine instance[citation needed]. This kind of environment is potentially more secure in the sense that it is less subject to "Quality of Service crosstalk" between VM instances[citation needed]; on the other hand, its security is typically dependent on the correctness of a larger and more complicated Trusted Computing Base[citation needed]. It is more commonly used in enterprise/commercial deployments[citation needed]. Examples include Microsoft Virtual Server, VMware ESX Server, and Xen.

[edit] Uses

Virtual private servers bridge the gap between shared web hosting services and dedicated hosting services, giving independence from other customers of the VPS service in software terms but at less cost than a physical dedicated server. As a VPS runs its own copy of its operating system, customers have superuser-level access to that operating system instance, and can install almost any software that runs on the OS. Certain software does not run well in a virtualized environment, including firewalls, anti-virus clients, and indeed virtualizers themselves; some VPS providers place further restrictions, but they are generally lax compared to those in shared hosting environments. Due to the number of virtualization clients typically running on a single machine, a VPS generally has limited processor time, RAM, and disk space.

Due to their isolated nature, VPSes have become common sandboxes for possibly-insecure public services or update testing. For example, a single physical server might have two virtual private servers running: one hosting the production-level (live) website, and a second which houses a copy of it. When updates to crucial parts of software need to be made, they can be tested in the second VPS, allowing for detailed testing to be conducted without requiring several physical servers.

Virtual private servers are also sometimes employed as honeypots, allowing a machine to deliberately run software with known security flaws without endangering the rest of the server. Multiple honeypots can be quickly set up via VPSes in this fashion.[citation needed]

[edit] Virtual private server hosting

A growing number of companies offer virtual private server hosting, or virtual dedicated server hosting as an extension for Web hosting services. Some web hosting companies call a Virtual Private Server a Virtual Dedicated Server/Dynamic Dedicated Server or the other way around.

[edit] Managed Hosting

Tools are provided to monitor and control the virtual machine.

[edit] Unmanaged Hosting

Typically only minimal services are provided, such as ssh console and reboot. Unmanaged VPS hosting is generally less expensive than managed VPS hosting.

[edit] Unmetered Hosting

Similar to unmanaged hosting but a fixed bitrate is offered so that it is not possible to exceed a monthly budget.

[edit] Virtualization software

For some of the software packages commonly used to provide platform virtualization, see comparison of platform virtual machines.

[edit] See also

• Emulation
• Operating system-level virtualization
• Paravirtualization
• Virtual machine

A dedicated hosting service, dedicated server, or managed hosting service is a type of Internet hosting where the client leases an entire server not shared with anyone. This is more flexible than shared hosting, as organizations have full control over the server(s), including choice of operating system, hardware, etc. Server administration can usually be provided by the hosting company as an add-on service. In some cases a dedicated server can offer less overhead and a larger return on investment. Dedicated servers are most often housed in data centers, similar to colocation facilities, providing redundant power sources and HVAC systems. In contrast to collocation, the server hardware is owned by the provider and in some cases they will provide support for your operating system or applications.

[edit] Operating system support

Availability, price and employee familiarity often determines which operating systems are offered on dedicated servers. Variations of Linux (open source operating systems) are often included at no charge to the customer. Commercial operating systems include Microsoft Windows Server, provided through a special program called Microsoft SPLA. Red Hat Enterprise is a commercial version of Linux offered to hosting providers on a monthly fee basis. The monthly fee provides OS updates through the Red Hat Network using an application called up2date. Other operating systems are available from the open source community at no charge. These include CentOS, Fedora Core, Debian, and many other Linux distributions or BSD systems FreeBSD, NetBSD, OpenBSD.

Support for any of the operating systems above typically depends on the level of management offered with a particular dedicated server plan. Operating system support may include updates to the core system in order to acquire the latest security fixes, patches, and system-wide vulnerability resolutions. Updates to core operating systems include kernel upgrades, service packs, application updates, and security patches that keep server secure and safe. Operating system updates and support relieves the burden of server management from the dedicated server owner.

[edit] Bandwidth and connectivity

Bandwidth refers to the data transfer rate or the amount of data that can be carried from one point to another in a given time period (usually a second) and is often represented in bits (of data) per second (bit/s). For example, visitors to your server, web site, or applications utilize bandwidth as the traffic moves from your server to the Internet and vice versa. Connectivity refers to the “access providers” that supply bandwidth, or data transfer rate, through various connection points across a network or footprint to one or multiple data centers where dedicated servers are housed.

Bandwidth measurements are defined (per telecom standards) as the following:

• First – 95th (measured using average bits and speed of transfer)
• Second – Unmetered (measured in speed or bits)
• Third – Total Transfer (measured in bytes transferred)

95th Method: Line Speed, billed on the 95th percentile, average or peak usage, refers to the speed in which data flows from the server or device. The measurement can be compared to mph (Miles Per Hour), or how fast something travels. Line Speed is measured using bits per second, kilobits per second, megabits per second, and gigabits per second.

Unmetered Method: The second bandwidth measurement is Unmetered service where providers cap or control the “top line” speed for a server. Top line speed in unmetered bandwidth is the total Mbit/s allocated to the server and configured on the switch level. For example, if you purchase 10 Mbit/s unmetered bandwidth, the top line speed would be 10 Mbit/s. 10 Mbit/s would result in the provider controlling the speed transfers take place while providing the ability for the dedicated server owner to not be charged with bandwidth overages. Unmetered bandwidth services usually incur an additional charge.

Total Transfer Method: Some providers will calculate the Total Transfer, the measurement of actual data leaving and arriving, measured in bytes. Measurement between providers varies and includes one of the following equations:

• Method 1: IN TRAFFIC + OUT TRAFFIC = TOTAL TRANSFER
• Method 2: IN TRAFFIC = TOTAL TRANSFER
• Method 3: OUT TRAFFIC = TOTAL TRANSFER

One of the reasons people choose to outsource dedicated servers is the availability of high powered networks from multiple providers. As dedicated server providers utilize massive amounts of bandwidth, they are able to secure lower volume based pricing to include a multi-provider blend of bandwidth. To achieve the same type of network without a multi-provider blend of bandwidth, a large investment in core routers, long term contracts, and expensive monthly bills would need to be in place. The expenses needed to develop a network without a multi-provider blend of bandwidth does not make sense economically for hosting providers.

Many dedicated server providers include a service level agreement based on network uptime. Some dedicated server hosting providers offer a 100% uptime guarantee on their network. By securing multiple vendors for connectivity and using redundant hardware, providers are able to guarantee higher uptimes; usually between 99-100% uptime if they are a higher quality provider. One aspect of higher quality providers is they are most likely to be multi-homed across multiple quality uplink providers, which in turn, provides significant redundancy in the event one goes down in addition to potentially improved routes to destinations.

Bandwidth consumption over the last several years has shifted from a per megabit usage model to a per gigabyte usage model. Bandwidth was traditionally measured in line speed access that included the ability to purchase needed megabits at a given monthly cost. As the shared hosting model developed, the trend towards gigabyte or total bytes transferred, replaced the megabit line speed model so dedicated server providers started offering per gigabyte.

Prominent players in the dedicated server market offer large amounts of bandwidth ranging from 500 gigabytes to 3000 gigabytes using the “overselling” model. It is not uncommon for major players to provide dedicated servers with 1Terabyte (TB) of bandwidth or higher. Usage models based on the byte level measurement usually include a given amount of bandwidth with each server and a price per gigabyte after a certain threshold has been reached. Expect to pay additional fees for bandwidth overage usage. For example, if a dedicated server has been given 3000 gigabytes of bandwidth per month and the customer uses 5000 gigabytes of bandwidth within the billing period, the additional 2000 gigabytes of bandwidth will be invoiced as bandwidth overage. Each provider has a different model for billing. As of yet, no industry standards have been set.

[edit] Management

To date, no industry standards have been set to clearly define the management role of dedicated server providers. What this means is that each provider will use industry standard terms, but each provider will define them differently. For some dedicated server providers, fully managed is defined as having a web based control panel while other providers define it as having dedicated system engineers readily available to handle all server and network related functions of the dedicated server provider.

Server management can include some or all of the following:

• Operating system updates
• Application updates
• Server monitoring
• Simple Network Management Protocol hardware monitoring
• Application monitoring
• Technical support
• Firewall services
• Antivirus updates
• Security audits
• DDoS protection and mitigation
• Intrusion detection
• Backups and restoration
• Disaster recovery
• DNS hosting service
• Load balancing
• Database administration
• Performance tuning
• Software installation and configuration
• User management
• Programming consultation

Dedicated hosting server providers define their level of management based on the services they provide. In comparison, fully managed could equal self managed from provider to provider.

Administrative maintenance of the operating system, often including upgrades, security patches, and sometimes even daemon updates are included. Differing levels of management may include adding users, domains, daemon configuration, or even custom programming.

Dedicated server hosting providers may provide the following types of server managed support:

• Fully Managed - Includes monitoring, software updates, reboots, security patches and operating system upgrades. Customers are completely hands-off.
• Managed - Includes medium level of management, monitoring, updates, and a limited amount of support. Customers may perform specific tasks.
• Self Managed - Includes regular monitoring and some maintenance. Customers provide most operations and tasks on dedicated server.
• Unmanaged - Little to no involvement from service provider. Customers provide all maintenance, upgrades, patches, and security.

Note: The provider will continue to maintain security on the network regardless of support level.

[edit] Security

Dedicated hosting server providers utilize extreme security measures to ensure the safety of data stored on their network of servers. Providers will often deploy various software programs for scanning systems and networks for obtrusive invaders, spammers, hackers, and other harmful problems such as Trojans, worms, eggdrops and crashers (Sending multiple connections). Linux and Windows use different software for security protection.

[edit] Software

Providers often bill for dedicated servers on a fixed monthly price to include specific software packages. Over the years, software vendors realized the significant market opportunity to bundle their software with dedicated servers. They have since started introducing pricing models that allow dedicated hosting providers the ability to purchase and resell software based on reduced monthly fees.

Microsoft offers software licenses through a program called the Service Provider License Agreement. The SPLA model provides use of Microsoft products through a monthly user or processor based fee. SPLA software includes the Windows Operating System, Microsoft SQL Server, Microsoft Exchange Server, Microsoft SharePoint and shoutcast hosting, and many other server based products.

Dedicated Server Providers usually offer the ability to select the software you want installed on a dedicated server. Depending on the overall usage of the server, this will include your choice of operating system, database, and specific applications. Servers can be customized and tailored specific to the customer’s needs and requirements.

Other software applications available are specialized web hosting specific programs called control panels. Control panel software is an all inclusive set of software applications, server applications, and automation tools that can be installed on a dedicated server. Control panels include integration into web servers, database applications, programming languages, application deployment, server administration tasks, and include the ability to automate tasks via a web based front end.

Most dedicated servers are packaged with a control panel. Control panels are often confused with management tools, but these control panels are actually web based automation tools created to help automate the process of web site creation and server management. Control panels should not be confused with a full server management solution by a dedicated hosting provider.

[edit] Limitations

Many providers do not allow IRC (bots, clients or daemons). This is due to rogue IRC users triggering DDoS attacks against the provider, which may overwhelm their networks, lowering service quality for all customers.

Adult content is disallowed by many providers as it may either be of questionable legality or consume large amounts of bandwidth.

A colocation centre (collocation center) ("colo") or carrier hotel is a type of data center where multiple customers locate network, server and storage gear and interconnect to a variety of telecommunications and other network service provider(s) with a minimum of cost and complexity.

Increasingly, organizations are recognizing the benefits of colocating their mission-critical equipment within a data centre. Colocation is becoming popular because of the time and cost savings a company can realize as result of using shared data centre infrastructure. Significant benefits of scale (large power and mechanical systems) result in large colocation facilities, typically 4500 to 9500 square metres (roughly 50000 to 100000 square feet). With IT and communications facilities in safe, secure hands, telecommunications, internet, ASP and content providers, as well as enterprises, enjoy less latency and the freedom to focus on their core business.

Additionally, customers reduce their traffic back-haul costs and free up their internal networks for other uses. Moreover, by outsourcing network traffic to a colocation service provider with greater bandwidth capacity, web site access speeds should improve considerably.

Major types of colocation customers are:

• Web commerce companies, who use the facilities for a safe environment and cost-effective, redundant connections to the Internet
• Major enterprises, who use the facility for disaster avoidance, offsite data backup and business continuity
• Telecommunication companies, who use the facilities to interexchange traffic with other telecommunications companies and access to potential clients

Most network access point facilities provide colocation.

[edit] Building features

A typical server rack, commonly seen in colocation.

• Fire protection systems, including passive and active design elements, as well as implementation of fire prevention programs in operations. Smoke detectors are usually installed to provide early warning of a developing fire by detecting particles generated by smoldering components prior to the development of flame. This allows investigation, interruption of power, and manual fire suppression using hand held fire extinguishers before the fire grows to a large size. A fire sprinkler system is often provided to control a full scale fire if it develops. Clean agent fire suppression gaseous systems are sometimes installed to suppress a fire earlier than the fire sprinkler system. Passive fire protection elements include the installation of fire walls around the space, so a fire can be restricted to a portion of the facility for a limited time in the event of the failure of the active fire protection systems, or if they are not installed.
• 19-inch racks for data equipment and servers, 23-inch racks for telecom equipment.
• Cabinets and cages for physical access control over tenants' equipment.
• Overhead cable rack (tray) and fiberguide, power cables usually on separate rack from data.
• Air conditioning is used to control the temperature and humidity in the space. ASHRAE recommends a temperature range of 20–25 °C and humidity range of 40–60% as optimal for electronic equipment conditions.[citation needed] The electrical power used by the electronic equipment is converted to heat, which is rejected to the ambient air in the data center space. Unless the heat is removed, the ambient temperature will rise, resulting in electronic equipment malfunction. By controlling the space air temperature, the server components at the board level are kept within the manufacturer's specified temperature/humidity range. Air conditioning systems help control space humidity within acceptable parameters by cooling the return space air below the dew point. Too much humidity and water may begin to condense on internal components. In case of a dry atmosphere, ancillary humidification systems may add water vapor to the space if the space humidity is too low, which can result in static electricity discharge problems which may damage components.
• Low-impedance electrical ground.
• Few, if any, windows.

[edit] Physical security

Most colocation centres have high levels of physical security, and may be guarded continuously. They may employ closed-circuit television camera.

Some colocation facilities require that employees escort customers, especially if there are not individual locked cages/cabinets for each customer. In other facilities, a PIN code or proximity card access system may allow customers access into the building, and individual cages/cabinets have locks. Biometric security measures, such as fingerprint recognition, voice recognition and "weight matching", are also becoming more commonplace in modern facilities.

[edit] Power

Colocation facilities generally have generators that start automatically when utility power fails, usually running on diesel fuel. These generators may have varying levels of redundancy, depending on how the facility is built.

Generators do not start instantaneously, so colocation facilities usually have battery backup systems. In many facilities, the operator of the facility provides large inverters to provide AC power from the batteries. In other cases, the customers may install smaller UPSes in their racks.

Some customers choose to use equipment that is powered directly by 48VDC (nominal) battery banks. This may provide better energy efficiency, and may reduce the number of parts that can fail.

An alternative to batteries is a motor generator connected to a flywheel and diesel engine.

Many colocation facilities can provide A and B power feeds to customer equipment, and high end servers and telecommunications equipment often can have two power supplies installed.

Colocation facilities are sometimes connected to multiple sections of the utility power grid for additional reliability.

[edit] Cooling

The operator of a colocation facility generally provides air conditioning for the computer and telecommunications equipment in the building. The cooling system generally includes some degree of redundancy

In older facilities, the cooling system capacity often limits the amount of equipment that can operate in the building, more so than the available square footage.

[edit] Internal connections

Colocation facility owners have differing rules regarding cross connects between their customers. These rules may allow customers to run such connections at no charge, or allow customers to order such connections for a significant monthly fee. They may allow customers to order cross connects to carriers, but not to other customers.

Some colocation centres feature a "meet-me-room" where the different carriers housed in the centre can efficiently exchange data.

Most peering points sit in colocation centres.

Because of the high concentration of servers inside larger colocation centres, most carriers will be interested in bringing direct connections to such buildings.

In many cases there will be a larger Internet Exchange hosted inside a colocation centre, where customers can connect for peering.

[edit] External connections

Colocation facilities generally have multiple locations for fiber optic cables to enter the building, to provide redundancy so that communications can continue if one bundle of cables is damaged.

[edit] External links

• Colocation at the Open Directory Project
• A Los Angeles 'Hotel' for Internet Carriers

A free web hosting service is a web hosting service that is free, usually advertisement-supported. Free web hosts will usually provide a subdomain (yoursite.example.com) or a directory (www.example.com/~yourname). In contrast, paid web hosts will usually provide a second-level domain along with the hosting (www.yourname.com). Many free hosts do allow use of separately-purchased domains. Rarely, a free host may also operate as a domain name registrar.

[edit] Features and limitations

Only a few free web hosts offer the basic package for free, although many that do specialize in this and make their money off of extensive advertising on customer's websites. Enhanced packages (with more features) are usually available for a cost. This allows users to try the service for an initial trial (see how it performs compared to other hosts), and then upgrade when (and if) needed.

Free hosting may have the following limitations:

• Limitation on the size of each hosted file
• Very small bandwidth per month compared to paid hosting
• Disabling on hotlinking of files
• File type restrictions (for example MP3, MPEG, ZIP etc.)
• Compulsory placement of the Webhosts' Banner or Popup ads into all web pages[1]
• No provided uptime guarantee
• No allowance of custom URLS, such as "http://www.domain.com". It has to be "http://www.provider.com/domain" or "http://domain.provider.com/".
• No allowance of pornographic nature.
• No customer installed advertising on the website.

Some free host may provide these extra features:

• A web based control panel
• Free email accounts for the domain or subdomain hosted
• File transfer via FTP
• Scripting languages: PHP, ASP, Perl etc.
• Relational databases such as MySQL
• Scheduled processes, known as cronjobs
• Other features such as guestbooks
• Forums and community resources not typical of paid hosts
• Reward systems which provide extra free products and services
• Have no data limitations offering unlimited space

[edit] Monetizing free webhosting

The majority of the hosting companies use free hosting to introduce their services, and as an entry point to their more expensive offerings. Generally they recoup their costs in one of two ways:

• Advertising - Selling online advertising on the customer sites is generally considered a fair trade - the reasoning is that high traffic sites are more expensive to host, but the additional traffic allows for additional ad impressions therefore covering the cost. For the web master, it can be a good trade if the advertising is of good quality and non-competitive. This is one of the main reasons that businesses do not use free hosting for their website. The majority of free hosting companies use this method.

• Referrals - Using a simple form of viral marketing, these providers rely on the users to spread the offer. The ratio of free to paid accounts is known, and by having each free user refer a number of friends, the hosting provider is able to get enough paid accounts to cover the cost.

• Resell Hosting - This is where someone starts up a hosting company, attracts lots of visitors, then sells the hosting company to someone else once it can no longer support itself. Once sold, this individual uses the money to start up multiple hosting ventures and sells each in turn.

Some hosting companies are using hybrid approaches that mix these tactics.

[edit] Methods of giving out web hosting

A few methods of giving out Free Webhosting to people by Webhosts

[edit] Instant Activation

Due to the risks of illegal, inappropriate, and abusive website, hosts with instant activation usually give very little storage space and monthly bandwidth. Other restrictions will likely also be in effect. The webhosts usually either require the users' web pages to display their banner ads, textlink ads, or popups; or else the users' files to be uploaded through a web-based file manager that display ads to the user uploading files.

Hosts with instant activation are often abused, such as link spamming.

[edit] Post for Hosting

Some free hosts require posting in a forum. Forum-based free hosting requires users to either reach a certain amount of posts before getting a free hosting account, or be an active contributor in the forum. Forum-based free hosting often work on a system of points where posts give points to a user and can be used as credits toward getting a hosting account or more resources. Typically, the forum where users have to post contains advertising as the hosts way of making a profit.

[edit] Forum applications

This method is popular, as the hosts can decide which applications to deny and allow. This is common when a popular forum has free hosting as an add-on service, rather than the other way around.

[edit] File hosting on webhosts

Most free web hosts discourage using their services for file or image hosting only, with no web page, since advertising is displayed on the web page. Because of this, hotlinking is usually disallowed on free hosts. Some free webhosts will also disallow files over a certain size (for example, 5 MB). However, there are free file hosting services which allow large files as well as hotlinking.

[edit] Co-branding and resellers

Some services offer co-branding services. These let you brand fixed plans with your own company. Other services, offer WHM or panel reselling. This allows the client to develop his or her own web hosting plans and business.

A shared web hosting service or virtual hosting service or derive host refers to a web hosting service where many websites reside on one web server connected to the Internet. Each site "sits" on its own partition, or section/place on the server to keep it separate from other sites. This is generally the most economical option for hosting as many people share the overall cost of server maintenance.

[edit] Description

The hosting service must include system administration since it is shared by many users; this is a benefit for users who do not want to deal with it, but a hindrance to power users who want more control. In general shared hosting will be inappropriate for users who require extensive software development outside what the hosting provider supports. Almost all applications intended to be on a standard web server work fine with a shared web hosting service. But on the other hand, shared hosting is cheaper than other types of hosting such as dedicated server hosting. Shared hosting usually has usage limits and most hosting providers have extensive reliability features in place. [1]

Shared hosting typically uses a web-based control panel system, such as cPanel, Ensim, DirectAdmin, Plesk, InterWorx, H-Sphere or one of many other control panel products. Most of the large hosting companies use their own custom developed control panel. Control panels and web interfaces can cause controversy however, since web hosting companies sometimes sell the right to use their control panel system to others. Attempting to recreate the functionality of a specific control panel is common, which leads to many lawsuits over patent infringement.[2]

In shared hosting, the provider is generally responsible for managing servers, installing server software, security updates, technical support, and other aspects of the service. Most servers are based on the Linux operating system and LAMP (software bundle), which is driven by the low cost of open source software, an example is a web2.0 host. But some providers offer Microsoft Windows-based or FreeBSD-based solutions. For example, the Plesk and Ensim control panels are both available for two operating systems, Linux and Windows. Versions for either OS have very similar interfaces and functionality, with the exception of OS-specific differences (for example, ASP.NET or Microsoft SQL Server support under Windows, and typically greater security and stability under Linux).

There are thousands of shared hosting providers in the United States alone. They range from mom-and-pop shops and small design firms to multi-million-dollar providers with hundreds of thousands of customers. A large portion of the shared web hosting market is driven through pay per click (PPC) advertising or Affiliate programs.

Shared web hosting can also be done privately by sharing the cost of running a server in a colocation centre; this is called cooperative hosting.

[edit] Implementation

Shared web hosting can be accomplished in two ways: name-based and IP-based, although some control panels allow a mix of name-based and IP-based on the one server.

[edit] Name-based

In name-based virtual hosting, also called shared IP hosting, the virtual hosts serve multiple hostnames on a single machine with a single IP address.

When a web browser requests a resource from a web server using HTTP/1.1 it includes the requested hostname as part of the request. The server uses this information to determine which web site to show the user.

[edit] IP-based

In IP-based virtual hosting, also called dedicated IP hosting, each virtual host has a different IP address. The web server is configured with multiple physical network interfaces, or virtual network interfaces on the same physical interface. The web server software uses the IP address the client connects to in order to determine which web site to show the user. The primary reason for a site to use a dedicated IP is to be able to use its own SSL certificate rather than a shared certificate.

[edit] Disadvantages

Name-based virtual hosts have some disadvantages:

• They do not properly support secure websites (HTTPS). All name-based virtual hosts using the same IP address must share the same digital certificate. This is because the SSL/TLS handshake takes place before the hostname is sent to the server. Thus the server doesn't know which encryption key to use when the connection is made. An extension to the TLS protocol, part of RFC 3546 - Transport Layer Security (TLS) Extensions, specifies a way for the client to provide the requested host name as part of the handshake, but it is not yet widely implemented. Some of the shared hosting providers require their customers to get Unique IP in order to properly set up HTTPS.
• If the Domain Name System is malfunctioning, it is harder to use a name-based virtually-hosted website. Ordinarily, in this case, the user could fall back to using the IP address to contact the system, as in http://127.0.0.1/ (invalid IP for example only). However, the web browser doesn't know what hostname to send to the server, but a name-based virtual host requires it. In this case, the default web host is sent back to the browser for that IP address. Therefore most hosters offer an alternative access method like http://127.0.0.1/~virtualhostname to provide access in such cases.
• They will not work with browsers that do not send the hostname as part of requests. This is true for older HTTP/1.0 browsers that have not retrofitted the host field feature from the HTTP/1.1 protocol. (The "Host" header that distinguishes between various DNS names sharing a single IP address was optional in HTTP/1.0; it is mandatory in HTTP/1.1, issued in 1999 as RFC 2616.) Since nearly every webbrowser that is currently used supports the HTTP/1.1 protocol and thus also virtual hosting, this is not a real issue.
• Improperly configured file permissions with shared file systems might give other (compromised) users or processes system-wide access to these files, such as credential files for database access or modification of existing files.

[edit] References

[edit] See also

• Hosting
• Web hosting service
• Dedicated hosting service
• Web server

  Clustered hosting is a type of web hosting that spreads the load of hosting across multiple physical machines ("nodes"), increasing availability and decreasing the chances of one service (for example FTP, or email) affecting another - for example web or database (e.g. MySQL). Many large websites run on clustered hosting solutions, for example, large discussion forums will tend to run using multiple front-end webservers with multiple back-end database servers.

  Typically, most hosting infrastructures are based on the paradigm of using a single physical machine to host multiple hosted services, including web, database, email, FTP and others. A single physical machine is not only a single point of failure, but also has finite capacity for traffic, that in practice can be troublesome for a busy website or for a website that is experiencing transient bursts in traffic.

  By clustering services across multiple hardware machines, and using load balancing you can eliminate single points of failure increasing availability of your website and other web services beyond that of ordinary single server hosting. A single server can require periodic reboots for software upgrades and the like, whereas in a clustered platform you can stagger the restarts such that the service is still available whilst still upgrading all necessary machines in the cluster.

  Clustered hosting is similar to cloud hosting, in that the resources of many machines are available for a website to utilize on demand, making scalability a large advantage to a clustered hosting solution.

Reseller hosting is a form of web hosting wherein the account owner has the ability to use his/her allotted hard drive space and bandwidth to host websites on behalf of third parties. The reseller purchases the host's services wholesale and then sells them to his customers for a profit. The certain portion of hard drive and bandwidth is allocated to reseller account. In order to achieve this the reseller may rent a dedicated server from a hosting company or resell shared hosting services. If the latter is the case the reseller is simply given the permission to sell a certain amount of disk space and bandwidth to his own customers without renting a server from a web hosting company he signed for a reseller account with.

The typical web hosting reseller might be a web design firm, web developer or systems integrator who offers web hosting as an add-on service. Reseller hosting is also an inexpensive way for web hosting entrepreneurs to start a company. Most reseller hosting plans allow resellers to create their own service plans and choose their own pricing structure. In many cases, resellers are able to establish their own branding via customized control panels and name servers.

Reseller hosting does not require extensive knowledge of the technical aspects of web hosting. Usually, the data center operator is responsible for maintaining network infrastructure and hardware, and the dedicated server owner configures/secures/updates the server. A reseller is responsible for interfacing with his/her own customer base, but any hardware, software and connectivity problems are typically forwarded to the server provider from whom the reseller plan was purchased. It should be noted that being a profitable reseller firm usually involves extensive advertising to get customers. While the monthly fees for major companies are only a few dollars a month it's high margin, and high advertising budgets, for established competitors a reseller must compete with.

Resellers can set up and manage customer accounts via a web interface, usually point and click "Control Panels."

Well-known Control Panels List:

• Cortex Provisioning System (Windows)
• WHM/cPanel (Unix)(Windows version coming soon)
• ehcp
• Plesk (Windows/Unix)
• DirectAdmin (Unix)
• Webmin (Unix)
• Ensim Pro (Windows/Unix)
• Helm (Windows)

FFmpeg hosting is a term that is used to refer to any "assortment of software which is available free, which helps in recording, converting and streaming a digital video or an audio", and to those domain registrars and web hosting companies which provide the above assortment of software to video hosting services. It is known as FFmpeg hosting due to the usage by several video hosting services of the FFmpeg software library in the server-side conversion of files with variously-encoded video and audio formats into a single preferred video or audio format that is both playable from the video hosting service and embeddable into any offsite webpage. As of 2008, the preferred format for the presentation of converted video is the .flv format.

[edit] FFmpeg-friendly webhosting

While there are thousands of web hosting services on the World Wide Web, only a tiny, but growing minority of these webhosts are willing to allow or accommodate video and audio hosting services, due to the rapid takeup of both bandwidth and disk space by user-uploaded video . The creation of video hosting services which sprung up in the years since the 2005 founding of YouTube, however, has created a demand for video-hosting friendly web hosts.

[edit] Basic needs from FFmpeg hosts

Most video hosting services need a dedicated or semi-dedicated server from the FFmpeg host, with shared bandwidth and virtual servers being sub-optimal solutions.

Weblog software (also called blog software or blogware) is a category of software which consists of a specialised form of Content Management Systems specifically designed for creating and maintaining weblogs.

[edit] Server models

Many weblog applications are available for users to download and install on their own systems. A wide variety of licenses are used by user hosted weblog software. Some of these are free and open-source that can be used, modified, and redistributed freely under free-software and open-source licenses. Others are proprietary software that may be licensed for a fee or have versions available free of charge.

Other weblog applications are offered only through their developers' hosts, either free of charge or for a fee. These typically include hosting service for the published blog itself, but some offer the option of using this hosted software to update a blog published

[edit] Clients

Maintenance through the Internet is a nearly universal feature of weblog software. This is usually done through a browser-based interface, enabling authors to create and update content on the site. Most software supports the use of external client software to update content using common APIs such as the MetaWeblog API and the Atom Publishing Protocol. Third party developers have created such clients, allowing bloggers to publish entries using desktop software rather than the web-based interface. WordPress Codex Wiki: Weblog Client has an extensive list of clients that support most APIs (not just WordPress). Examples include ecto and MarsEdit.

[edit] Features

• Title, the main title, or headline, of the post.
• Body, main content of the post.
• Permalink, the URL of the full, individual article.
• Post Date, date and time the post was published.

A blog entry optionally includes the following:

• Comments

Comments are a way to provide discussion on blog entries. Readers can leave a comment on a post, which can correct errors or contain their opinion on the post or the post's subject. Services like coComment aim to ease discussion through comments, by allowing tracking of them.

• Categories (or tags) - subjects that the entry discusses
• Trackback and or pingback - links to other sites that refer to the entry

[edit] Other applications

Most weblogs have features such as facilitating authoring and editing of blog posts or articles, various linking and web syndication features, and the ability to easily publish the blog to the world wide web. Some services or organizations are also creating weblog applications with extended features to aid communication, such as the wiki capabilities in Socialtext and Traction TeamPage.

Many weblog applications allow the user to define static pages of content which can often be placed into a hierarchy or tree. Pages differ from blog posts in that the content is largely static and not time related. Pages are often used to present information about the blog and its authors. Extensive use of pages can result in a blog that looks more like a website. [1]

Most weblog applications support English and many other languages. The user selects a language during installation.

Weblog applications usually offer web syndication service either in the form of RSS or Atom. This allows for other software such as feed aggregators to maintain a current summary of the blog's content.

Post moderation requires the people who want to comment on articles that are posted on a blog to be approved before the comments are visible to the world. It could also mean in some cases where multiple people have accounts and the ability to post new items to the blog that new content must be approved by a moderator or administrator before it shows up on the main page. Weblog applications use various user account systems that allow readers to post comments to a particular blog. For instance, users with Blogger accounts may comment on any Blogger blog. Other weblog applications allow users to post content or comments only to blogs where they have an account.

The Post API can vary greatly depending on the system in use. Some types of blogware have plugins for Firefox that integrate into the browser's menus so that right-clicking on selected text on any given webpage will bring up a small window that allows the user to post to their blog. Other types of blogware that do not have this type of interface require a person to fill out a form online. The form that is required for posting material to a blog depends on the type of blogware. Some types such as Movable Type contain a greater number of form fields and choices than ones such as Blogger.

Most types of blogware support adding thumbnail images within blog posts. Photo blogging is a separate genre of blogging that deals primarily with images.

A new trend in blogging software is drag and drop WYSIWYG editing which allows a user to easily modify page elements on the fly. A few companies who pioneering this effort include Squarespace and Weebly.

[edit] Documentation and support

Different blogware packages feature varying levels of community support and documentation. Because the installation of some types of software requires an advanced knowledge of computer administration, community support and documentation can be very helpful. The web servers and database software can be more difficult to install than the blogware itself. Also a strong and active community surrounding the blogware gives advice on integrating the blogware into a personal site.

[edit] Examples

A partial list of notable weblog software follows:

[edit] User hosted platforms

Software packages installed by weblog authors to run on their own servers.

[edit] Free and open source software

These software packages are offered as free and open source software:

• Apache Roller (Java-based)
• b2evolution (PHP/MySQL)
• blosxom (Perl)
• Bloog (Google App Engine/ Python)
• DotNetNuke (VB.NET/ASP.NET)
• Drupal (PHP)
• Frog CMS (PHP)
• Elgg (PHP)
• Habari (PHP)
• Jaws (PHP)
• Joomla (PHP)
• Livejournal (Perl) (Also available, developer hosted)
• LifeType (PHP)
• Movable Type (Perl)
• Nucleus CMS (PHP)
• Serendipity (PHP)
• Slash (Perl)
• Subtext (C#/ASP.NET)
• Textpattern (PHP)
• Typo (Ruby on Rails)
• WordPress (PHP)

[edit] Proprietary software

These packages are under a proprietary software license. They may require the purchase of a license key to use them. The specific licensing terms vary but some are free of charge for personal or non-commercial use.

• Community Server (also offered in developer-hosted form as CommunityServer.com)
• ExpressionEngine
• Traction TeamPage
• Windows Live Writer

[edit] Developer-hosted

Software services operated by the developer, requiring no software installation for the weblog author:

• Blogger
• LiveJournal
• MySpace
• Open Diary
• Skyrock
• TypePad
• Typo
• Windows Live Spaces
• Wordpress.com
• Xanga
• Vox

A guild hosting or clan hosting service is a specialized type of web hosting service designed to support online gaming communities, generally referred to as guilds or clans. They vary from game server hosting in that the focus of such companies is to provide applications and communication tools outside of the gaming environments themselves.

[edit] Typical Features

The services typically offered by such a service include:

• Public and/or private forums for members to communicate with each other, or other tools for communications such as instant messaging or chat servers.
• Tools for tracking the roster of characters that a player might have in an MMORPG.
• An application for scheduling and organizing raids, tournaments and other gaming events.
• Applications for tracking treasure, items, or points accrued toward redeeming treasure (often referred to as a DKP system).

[edit] History

Originally, most people who decided to create a website for their guild used bulletin board software such as vBulletin and phpBB on traditional web hosting services. However, as the complexity of online games increased--accompanied by larger memberships, needs for more sophisticated scheduling tools, and roster-management features. One of the earliest such companies was GuildPortal, formed in 2001.[1] In 2006, GamerDNA combined the features of a social network with guild hosting, to provide guilds with the ability to network with each other, as well as their own members.[2]

Guild hosting services address a guild's basic need to have an online presence and allow guild members to communicate with each other outside of the game. While it is possible for any guild to do this on their own, setting up and maintaining a site requires constant maintenance, upgrades and integration of new software. One of the key reasons for the popularity of guild hosting services is their focus on relieving the guild from this overhead and freeing them up to spend more time playing the game. In 2006 Guild Launch was formed to directly address the need for reducing this management overhead, to expand the existing social network of the guild into other areas, and to build long term communities within the guild by delivering high quality and easy to use tools.[3] Also launching in 2006 was MMO Guildsites, a option with many advanced features, some of which have been made freely available for use with any hosting service.[4] In 2007 Guildomatic was launched to provide a guild hosting platform specifically for World of Warcraft guilds. [5] In 2008 MyGuildHost, a new player in guild hosting, launched version 2 of their guild hosting and management control panel -- powered by open source PHP and AJAX technologies. [6] In September 2008 GameStreet.net, a gaming social network launched its own brand of guild hosting with extreme flexiblity and ease of setup with a drag-and-drop designer for guild managers. [7]

[edit] References

1. ^ GuildPortal FAQ, http://www.guildportal.com/FAQ.aspx?FAQEntry=47
2. ^ Gamasutra, Industry News, Jan 17. 2007, http://www.gamasutra.com/php-bin/news_index.php?story=12425
3. ^ "Henrico firm unites gamers", Richmond Times Dispatch (2007-04-29). Retrieved on 16 July 2007. 
4. ^ WoW Insider, MMO Guildsites releases Armory Widget
5. ^ Console News, Guildomatic launches World of Warcraft guild hosting
6. ^ MyGuildHost Developer Blog, New Admin Panel
7. ^ GameStreet News, Guild Hosting System Goes Live

An image hosting service allows individuals to upload images to an Internet website. The image host will then store the image onto its server, and show the individual different types of code to allow others to view that image.

[edit] How it works

Typically image hosting websites provide an upload interface; a form in which you specify the location of an image file on your local computer file system (using a browse button). After pressing a “Submit” button the file is uploaded to the image host’s server. Some image hosts allow you to specify multiple files at once, in this form, or the ability to upload one ZIP file containing multiple images. Additionally, some hosts allow FTP access, where single or multiple files can be uploaded in one session using FTP software or an FTP-capable browser.

After this process, your image is hosted on their server. Typically this means it is available on the web (to the public). You may also be allowed to make inline links to the hosted image, to embed it on other websites e.g.

• Linking with HTML code
• Linking with BBcode
• A clickable thumbnail that is linked to the full image

Usually, the image host will put restrictions on the maximum image size allowed, or the maximum space or bandwidth allowed per user. Due to bandwidth costs, free services usually offer relatively modest size limits per image when compared to paid services, but allow users hotlinking their images. Individuals needing to host large images should consider purchasing image hosting services or purchasing webhosting services, so that they may operate their own website.

[edit] Tools

Image hosts also allow tools such as the ability to create photoblogs/galleries with your images, or add them to a slideshow for easier viewing. Some offer more advanced tools such as the ability for an individual to add notes to an image they uploaded, sideloaders, or browser sidebars. Other hosts have introduced novel features such as the ability to automatically resize images down to a user-selected size. A Flickr tool allows you to upload photos using a camera phone with email capability.[1]

[edit] Cost

Many image hosts are free. Of the free image hosts, the vast majority are supported by advertisement, mostly on their top pages, thumbnail pages, or 'not found' pages. Showing advertisements to users has enabled image size and bandwidth limits to increase.

Some free hosts have optional paid image hosting functions, while other hosts offer only paid services. Features and storage available are generally better for paid services, while cost is still much less than the cost of purchasing webhosting to operate a website. Paid services often allow users to have password protected photo albums, customizable skins, and customized subdomains. There are many other paid services available that offer different packages of features, options, and costs.

A video hosting service allows individuals to upload video clips to an Internet website. The video host will then store the video on its server, and show the individual different types of code to allow others to view this video. The website, mainly used as the video hosting website, is usually called the video sharing website.

Further information: List of video sharing websites

[edit] Impetus

Because many users do not have unlimited web space, either as a paid service, or through an ISP offering, video hosting services are becoming increasingly popular, especially with the explosion in popularity of blogs, forums, and other interactive pages.

The mass market for camera phones has increased the supply of user-generated video. Traditional methods of personal video distribution, such as making a DVD to show to friends at home, are unsuited to the low resolution and high volume of camera phone clips. In contrast, current broadband Internet connections are well suited to serving the quality of video shot on mobile phones. Most people do not own web servers, and this has created demand for user-generated video content hosting, which the likes of YouTube are catering to.

[edit] Purpose of Video Hosts (for users)

• Save on bandwidth costs, often eliminating costs entirely
• Creating a common place
• Make a hassle-free experience, where uploading a video and streaming or embedding would normally require advanced programming knowledge. It is now commonly achieved through a web browser, with little or no programming experience.

[edit] Copyright issues

Wikipedia hosts around 200 videos in the Ogg format on its servers. Wikipedia actively discourages non-free videos and formats: videos added to Wikipedia are supposed to be freely available for reuse. This contrasts with video hosting services such as YouTube, which can hold copyrighted material, though some rights must be given up to such companies in return for the hosting.

[edit] Mobile video hosting

Main article: Mobile Web content management system

A more recent application of the video hosting services is in the Mobile Web arena, where video and other mobile content can be delivered to, and easily accessed by mobile devices. While video-hosting services such as YouTube have developed means by which video can be watched on mobile devices, mobile-oriented web-based frontends for video hosting services that possess equal access and capability to desktop-oriented web services have yet to be developed.

A wiki farm allows multiple users to create multiple individual wikis. Whenever multiple individual wikis run off of one installation of wiki programming, this is a wiki farm.[1] Wiki farms are run from a server or an array of servers in which core wiki code is installed.[clarification needed]

Prior to Wiki Farms, the administrator of multiple wikis had to install each wiki independently. This resulted in much wasted time, deploying redundant code and configurations on the server. With wiki farms this process is greatly simplified. The administrator established unique space on the server(s) (the field) and uses the core installed code (in the farm) to execute the functions of each individual wiki.[2]

Non-commercial and commercial Wiki farms are available for users and online communities. While most of the wiki farms allow anyone to open their own Wiki, some impose restrictions. Many wiki farm companies generate revenue through the insertion of advertisements, but often allow payment of a monthly fee as an alternative to accepting ads.

[edit] General

The following tables compare general information for several wiki farms; however, more than 100 wiki farms have been created.[3] Further information can be found at the websites themselves, or in the linked article for some of the more notable ones. This article is not all-inclusive or necessarily up to date. It does not review or endorse any wiki farm, nor does it include any advertising hyperbole. See the external links at the end for more info, reviews, forums, etc.. The Alexa traffic rankings are not accurate for those wiki farms that allow some of their hosted wikis to have separate domain names. In those cases there may be some additional Alexa rankings listed below for some of the larger individual wikis in a wiki farm. The Wikis are normally provided with a standard layout, or a choice of layouts, usually known as skins. Some wiki farms allow the layout to be customised using cascading style sheets (css).

Wiki farm	Alexa[4]	Cost?	Ad?	Content license
@wiki	&0000000000170000.000000170,000 [5]	Free	Yes
BluWiki	&0000000000085000.00000085,000 [6]	Free	No	GFDL
BrainKeeper	&0000000000550000.000000550,000 [7]	Nonfree	?
BusinessWiki	&0000000000012000.00000012,000 [8]	Free (3 users) / Paid (14 days trial)	No	GPL
Central Desktop	&0000000000025000.00000025,000 [9]	?	?
ClearWiki	&0000000000450000.000000450,000 [10]	Free/Paid	?
Confluence Hosted	&0000000000030000.00000030,000 [11]	Paid[12]	?
CustomerVision BizWiki	&0000000001600000.0000001,600,000 [13]	Paid	?
EditMe	&0000000000110000.000000110,000 [14]	Paid	?
EditThis.info	&0000000000090000.00000090,000 [15]	Free	Text
eTouch SamePage	&0000000000450000.000000450,000 [16]	Paid	?
eurekster swicki			?
GROU.PS SuperWiki	&0000000000064000.00000064,000 [17]	Free	No	Any
HelpingStudents.org	&0000000005300000.0000005,300,000 [18]	Free/paid	?	License
Hive Wiki	&0000000002500000.0000002,500,000 [19]	Free	?
HOAwiki	&0000000002400000.0000002,400,000 [20]	Paid	No	Users Choice
Intodit	&0000000000350000.000000350,000 [21]	Free	AS
MojWiki	&0000000004300000.0000004,300,000 [22]	Free	AS
MyFreeWiki (en, fr)	&0000000002000000.0000002,000,000 [23]	Free	No	User Choice
Netcipia	&0000000000850000.000000850,000 [24]	Free[25]	No
nexdo (formerly Partnertext)	&0000000007100000.0000007,100,000 [26]	Free/paid	?
Oddwiki	&0000000000500000.000000500,000 [27]	Free	?
On-wiki	&0000000000700000.000000700,000 [28]	Free	Yes
OpenTeams	&0000000002300000.0000002,300,000 [29]	Paid[30]	?
Ourproject.org	&0000000000190000.000000190,000 [31]	Free	No	Copyleft (choice of Creative Commons, GNU FDL, other licenses)
PAUX	&0000000008500000.0000008,500,000 [32]	Free/paid	?	Copyleft license
PBwiki	&0000000000003000.0000003,000 [33]	Free/paid	Yes
PicoWiki	&0000000001500000.0000001,500,000 [34]	Free/donationware - for personal wikis optimized for iPhone and smartphones	No	user choice
ProjectForum	&0000000000750000.000000750,000 [35]	Paid	?
ProjectLocker	&0000000001900000.0000001,900,000 [36]	Paid	?
Referata	&0000000000780000.000000780,000 [37]	Free/paid	No	User choice (via site settings), default is Creative Commons by-sa[38]
SeedWiki	&0000000000340000.000000340,000 [39]	Free/paid	No
SnoutHold Cospire	&0000000001500000.0000001,500,000 [40]	Free	?
Socialtext Workspace Hosted	&Expression error: Unrecognised punctuation character ","Expression error: Unrecognised punctuation character ","Expression error: Unrecognised punctuation character ","Expression error: Unrecognised punctuation character ","Expression error: Unrecognised punctuation character ","Expression error: Unrecognised punctuation character ","Expression error: Unrecognised punctuation character ","Expression error: Unrecognised punctuation character ","Expression error: Unrecognised punctuation character ","Expression error: Unrecognised punctuation character ","Expression error: Unrecognised punctuation character ","Expression error: Unrecognised punctuation character ","Expression error: Unrecognised punctuation character ","Expression error: Unrecognised punctuation character ","Expression error: Unrecognised punctuation character ","Expression error: Unrecognised punctuation character ",".Expression error: Unrecognised punctuation character ","51,663 [41]	Paid [42]	No	Wiki creators can set their own.
Swirrl	&0000000001600000.0000001,600,000 [43]	Free/Paid	No	Terms Of Service
Uwiki.com	&0000000007600000.0000007,600,000 [44]	Free	?
ViaWiki	&0000000005300000.0000005,300,000 [45]	Free/paid. FREE plan includes 25 megabytes of storage and a maximum of 5 users.	?	GoogleAd on free accounts
Wetpaint	&0000000000002000.0000002,000 [46]	Free/Paid	AS	Creative Commons
Wik.is	&0000000000070000.00000070,000 [47]	Free/paid	?
Wikia	&0000000000000300.000000300 [48]	Free	Yes	GFDL
Wikidot	&0000000000005013.0000005,013 [49]	Free/paid	Yes/No	By default Creative Commons, GNU FDL, other licenses as requested
Wikihost.org	&0000000000190000.000000190,000 [50]	Free	Yes	By default Creative Commons, others as needed
Wiki-site.com	&0000000000120000.000000120,000 [51]	Free/paid	AS	Wiki creators can set their own
Wikispaces	&0000000000004500.0000004,500 [52]	Free/paid	Yes/No	Choice of Creative Commons, GNU FDL, other licenses
Wiki Spot	&0000000000450000.000000450,000 [53], &0000000000096000.00000096,000 [54]	Free[55]	No	User choice, default Creative Commons Attribution
Wikkii	&0000000000550000.000000550,000 [56]	Free	Yes
WikyBlog.com	&0000000000550000.000000550,000 [57]	Free	?	Any, integrated Creative Commons licenses
XWiki	&0000000000200000.000000200,000 [58]	Free/paid	No	Any
Russian wiki community	&0000000002200000.0000002,200,000 [59]	negotiatable	?	negotiatable
YourWiki	&0000000002462000.0000002,462,000 [60]	Free and Premium	AS	GFDL
Wiki farm	Alexa[61]	Cost?	Ad?	Content license

[edit] Technical

Wiki farm	WYSIWYG editing	Features	Base wiki engine	Multilingual support	Syntax support
@wiki	Yes	Selectable edit-mode (WikiText or WYSIWYG or text), access control, file uploads, importing, full-text search, and RSS abilities.	[?] (custom)	English, Chinese, Korean and others	Some HTML,[3] JavaScript, Math formulas
BluWiki	?	No subscription needed, users can make new wiki articles. Subdomains are supported. [2]	MediaWiki 1.6.7	Supports English, German, Spanish, French, and most other languages. Incorrect support of Russian.	MediaWiki, Some HTML,[3] JavaScript, Math formulas
BrainKeeper	Yes	Access control, full-text search, calendaring, single sign-on to multiple projects, project templates, RSS enabled.	[?] (custom)		Some HTML,[3] no script No formulas
BusinessWiki	Yes	Visual editing, Folders and tags, Easy PDF document creating, Backups mechanisms, Multiple feeds allowing to track information and notify about changes (RSS, mail, mobile web), Comprehensive user guide, Compatibility with MediaWIki (database standard, wiki-text) and Open-source version for your safety. Each site gets a subdomain on .onbusinesswiki.com.	MediaWiki	English	WikiText, HTML
Central Desktop	Yes	Access control, full-text search, calendaring, single sign-on to multiple projects, project templates, RSS enabled.	[?] (custom)		HTML,[3] CSS/templating No formulas
ClearWiki	Yes	Private secure wikis (with sub-domains) - each wiki has own physical database. File storage, version control, full text search (incl docs/files), to-do lists, RSS enabled, blogs, discussions, image galleries (with thumbnailing), meta-tagging (labelling), content starring, teams/groups.	[?] (custom)	English only	Some HTML,[3] WYSIWYG edit
Confluence Hosted	Yes	Wiki markup language, plugins, SSL, file storage, permissioning, WebDAV.			HTML plugin script plugin No formulas
CustomerVision BizWiki	Yes	Access control, page templates, domain mapping, solution templates include Sales Support, and Learning Support.	[?] (custom)
EditMe		Subscription-based, SSL Encryption, and Custom Domain Support.	Java-based (custom)		All HTML,[3] JavaScript, No formulas
EditThis.info	?	Unlimited pages and users (but no longer upload of photos[3]), wiki spam protection, 25MB of file upload space, and RSS feeds. Apparently allows free wikis to profit from Google AdSense[62].	MediaWiki 1.5.5		Some HTML,[3] JavaScript, No formulas
eTouch SamePage	Yes	Project management, permissioning, administration and support for multiple domains.	eTouch CMS (custom, powered by)
GROU.PS SuperWiki	Yes	Secure SSL encrypted login, Advanced Privacy and Moderation Settings, Revisions, Real-Time Chat (optional), RSS & Email Alerts for your group members, Categories (Subfolders), Wiki Comments (optional), Multilingual; all texts customizable, Unlimited file upload space, Domain masking, Customizable templates.	[?] (custom)	English, French, Greek, Turkish, Hebrew, Swedish and extensible	All HTML
HelpingStudents.org	Yes	Java server pages, scripts and plugin wiki options for school administrators and teachers that provide parental information resources WikiText and HTML editing, metasearch, factoring, permissioning, SSL Encryption, Private Intranet implementation with public integration administration and support.	JSPWiki
Hive Wiki	?	WikiText and HTML editing, metasearch, factoring, permissioning, administration and support for multiple domains and publicly creatable subdomains	.NET-based (custom)
HOAwiki	Yes	Hosted and supported TikiWiki CMS/groupware. [63]	TikiWiki 2.2 (last stable)	Multilingual to 30 languages	HTML, Smarty code, javascript
Intodit	Yes	WYSIWYG editing only, custom page hierarchies, Comment and Reply forums, group rating, layout templates, keyword search, tags, skins, RSS, profiles, activity report, No changes preview. Supported browsers: Internet Explorer, Firefox, Safari.	[?] (custom)		No HTML,[3] Unknown script No formulas
MojWiki	?	In Slovenian language.	MoinMoin	Slovenian
MyFreeWiki	Yes	Easy and Fast, plaintext editors available. Integrated photo gallery.	Enzym (custom)	English and French	All HTML, Javascript
Netcipia	Yes	Blog, public and private wiki, 2GB per wiki created, no time limit, right management	XWiki	English only	All HTML, JavaScript, No math
nexdo (formerly Partnertext)	Yes	WYSIWYG HTML editing	[?] (custom)		All HTML,[3] unknown script No formulas
Oddwiki	?		Oddmuse
On-wiki	Yes	Attachments, multimedia, writing formulaes, plotting graphs, raw HTML	MoinMoin
OpenTeams	Yes	3-pane drag-and-drop Ajax-based interface similar to email and newsfeed readers, private secure wiki spaces (including invitation-only and a domain security option based on validated email domains, i.e. "Everybody with email@domain.com"), tags, blog, bliki, "What's New" views, draft autosaving, discussion, attachments with version history, SSL, unlimited spaces, pages, edits, versions, storage, and bandwidth.	[?] (custom)
Ourproject.org	Yes	It offers freely a wide collection of services for multi-purpose free/libre projects (not only free software: free knowledge), including wikis, mailing lists, forums, FTP, subdomains, hosting, ddbb, email alias, backups, CVS/SVN, Task management...	MoinMoin	Supports English, Spanish, French, and many other languages.
PAUX		Password-protected wikis on .dreusicke-verlag.de. No page limits, SSL, picture gallery included.	[?] (custom)		Some HTML,[3] unknown script Math formulas
PBwiki		Password-protected wikis on .pbwiki.com subdomain (higher-level paid plans allow use of a custom URL). No page limits, SSL, RSS & Atom, ZIP backups, diffs, six wiki "skins", file uploads, page hiding, page locking. Over 490,000 wikis hosted. One level of folders used to organize pages. Folder- and page-level access controls available to paying customers and business users. Free accounts limited to 10 MB, paying accounts get up to 10 GB.	[?] (custom)		All HTML,[3] JavaScript, LaTeX formulas
ProjectForum			[?] (custom)		Optional HTML, unknown script No formulas[3]
ProjectLocker		Focused on providing software development tools as a service. Wiki features include Unlimited document storage, Custom access profiles for partners, customers, and managers, Support for attachments on documents, Privacy Commitment - Your Data is Yours Alone, Secure access via SSL, RAID 1 redundant storage of all data, Nightly backups, 24/7 Server Monitoring	[?] (custom)
Referata	No	A semantic wiki hosting site. Uses MediaWiki, along with Semantic MediaWiki and related extensions, to enable wikis to serve as collaborative databases, with custom forms, result tables, calendars, maps, etc. Free wikis are limited to 5 MB of uploaded file storage; there is no limit on the size of the wiki text. Every wiki gets a subdomain of referata.com, although some paid service levels also allow for custom domains. [64]	MediaWiki 1.13.1	Dozens of languages, although help pages are mostly in English	Standard MediaWiki scripting, math formulas
Riters.com		Line document collaboration service and Wiki farm	MoinMoin
SeedWiki	Yes	cross-platform WYSIWYG editing, stylesheets, subdomains.seedwiki.com, wiki-mode, subscriptions; paid option for having one's own domain that the wiki-owner can tag on to his wiki	[?] (custom)		All HTML,[3] JavaScript and Seedwiki widgets Plugin formulas
SnoutHold Cospire	Yes	Permissions, public/private security models, ratings, feedback mechanisms, search engine, category organizer, profiles	[?] (custom)
Socialtext Workspace	Yes	Enterprise Wiki. Supports text, rich text, embedded images, video, and attachments (including from email).	Derived from Kwiki
Swirrl	Yes	Text pages, data sets (with spreadsheet-like user interface), permissions, public/private pages, versioning, searching, tags	Custom	Enter content in many languages, user interface in English
Uwiki.com		In Chinese	DokuWiki	Chinese
ViaWiki	Yes	Free version is ad-supported, paid version has option of using own domain, attach files, no limit on number of pages and backups, max 5GB (pain version)[65]	Deki Wiki
Wetpaint	Yes	WYSIWYG editing only, custom page hierarchies, Comment and Reply forums with comment ratings, access control, keyword search, tags, tag filtering, skins, RSS, page locking, profiles, site activity report, page and comment watching. No page permission settings. No changes preview. Supported browsers: Internet Explorer, Firefox.	Java-based (custom)		No HTML,[3] Unknown script No formulas
Wik.is	Yes	Access control, full-text search (including file attachments), document management, light project management, database, project templates, RSS enabled, stores in XML, Deki Wiki a full featured engine (a MediaWiki fork). Free account 1 GB. Paid account ($60/yr) 10 GB.	Deki Wiki
Wikia	No	Wiki hosting service created in 2004, formerly known as Wikicities. All wikis have common login and preferences. Single sign-on to multiple projects. Database download available. Creation of a wiki is subject to approval; must have a large potential audience and be likely to attract enough editors. Projects which overlap existing Wikia or Wikimedia are not accepted. No means to close an inactive wiki, even if the community has moved elsewhere. Wikia domains, names, and identifiers owned by Wikia Inc, not the respective communities; in a recent change of policies, all communities are being migrated to .wikia.com subdomains. There is also a "Scratchpad" wiki subdivided into categories, which welcomes all content.	MediaWiki 1.13.2	All languages Wikipedia exists for (and some more); Community Support in English, Chinese, German, Japanese, Spanish and Portuguese.	Some HTML,[3] JavaScript, Math formulas
Wikidot		Each site gets a subdomain on .wikidot.com (like mywiki.wikidot.com). Also there is possibility to map a custom domain (like mywiki.com -- if previously registered by the wiki owner) for free. One can optionally allow Wikidot to display ads on their wiki and get 80% of revenue. RSS import/export, private RSS feeds for Users (notifications and watched items), RSS for page changes and forum, customizable themes (every item can be styled with CSS), advanced forum for each Site. Custom page hierarchies, searching, advanced page (full/section/append) edit locking, blocking users and IP addresses. Private messages between users. Uses Ajax for clean and fast (no browser page-reload) interface. SEO-friendly. No limits on site size. Public and private wikis. Lots of widgets, that allow to embed a video from YouTube, GoogleVideo, photos from Flickr, chats from Meebo and many more). Each user can create up to 20 wiki sites and be a member of an unlimited number of wikis.	Modified Text_Wiki engine	English, Polish, Russian and Community support in French, German, ... more to come.	No HTML,[3] CSS styling LaTeX math formulas
Wikihost.org		100 MB space, File and Image upload, User authentication, Private wikis, Subdomains for wikis larger than 30 pages, RSS, Edit locking, Fulltext search, Email notifications, Complete wiki export, Unlimited pages, Unlimited Revisions, Diff function, Revert of old revisions	GeboGebo
Wiki-site.com	Yes	Wiki farm with unlimited pages and users, wiki spam protection, user rights control for paid accounts. Interface in 150 languages. A free *.wiki-site.com domain is offered. Google text-ads added to the right sidebar for free accounts.	MediaWiki 1.11.0	English, French, Spanish, Italian, German and over 70 other languages.	Some HTML,[3] JavaScript, Math formulas
Wikispaces	Yes	Clean easy to use interface, users get a subdomain on wikispaces.com. Free version supported by Google ads - Wikispaces ads can be turned off for a fee. No limits on numbers of pages, spaces, or members. Full RSS support; easy space backups in zip and tgz. Blog import function/ integration with Blogger.com and Typepad. Themes and stylesheets can be customized. Private label service available.	[?] (custom)		Optional HTML,[3] Unknown script Math formulas
Wiki Spot		No advertising, user accounts work on all wikis, use bookmarks and track changes across multiple wikis. Customizable CSS by wiki and user CSS. Simple, intuitive syntax. No limits on pages/disk space. RSS feeds available on all pages. Easy to create a wiki and configure settings.	Sycamore
Wikkii.com		Features complete back-end control with full FTP and Cpanel access. Initially 1GB storage and 10GB bandwidth. Install any wiki script. Add unlimited custom templates, add-ons, and plugins. Free domain names for popular wikis.	MediaWiki or User Chosen
WikyBlog.com		No advertising on user accounts, unlimited custom skins, AJAX enhanced tabbed interface	WikyBlog (custom)	UTF-8 with English, Arabic, Russian, Turkish, Spanish and Korean	Some HTML,[3] No script No math
XWiki		custom skin, unlimited users	XWiki		All HTML,[3] velocity/groovy No formulas
Russian wiki community		negotiatable	MediaWiki 1.5.8	UTF-8/Russian	Some HTML,[3] JavaScript, Math formulas
Wiki farm	WYSIWYG editing	Features	Wiki engine	Multilingual support	Syntax support

[edit] See also

• List of wikis
• Wiki software
• List of wiki software
• Comparison of wiki software - feature-table comparison of common wiki software.
• List of collaborative software
• Collaborative software
• Collaborative real-time editor

[edit] Notes

An application service provider (ASP) is a business that provides computer-based services to customers over a network. Software offered using an ASP model is also sometimes called On-demand software or software as a service (SaaS). The most limited sense of this business is that of providing access to a particular application program (such as customer relationship management) using a standard protocol such as HTTP.

The need for ASPs has evolved from the increasing costs of specialized software that have far exceeded the price range of small to medium sized businesses. As well, the growing complexities of software have led to huge costs in distributing the software to end-users. Through ASPs, the complexities and costs of such software can be cut down. In addition, the issues of upgrading have been eliminated from the end-firm by placing the onus on the ASP to maintain up-to-date services, 24 x 7 technical support, physical and electronic security and in-built support for business continuity and flexible working.

The importance of this marketplace is reflected by its size. As of early 2003[update], estimates of the United States market range from 1.5 to 4 billion dollars. Clients for ASP services include businesses, government organizations, non-profits, and membership organizations.

[edit] Provider types

There are several forms of ASP business. These are:

• A specialist or functional ASP delivers a single application, such as credit card payment processing or timesheet services;
• A vertical market ASP delivers a solution package for a specific customer type, such as a dental practice;
• An enterprise ASP delivers broad spectrum solutions;
• A local ASP delivers small business services within a limited area.

Some analysts identify a volume ASP as a fifth type. This is basically a specialist ASP that offers a low cost packaged solution via their own website. PayPal was an instance of this type, and their volume was one way to lower the unit cost of each transaction.

In addition to these types, some large multi-line companies (such as IBM), use ASP concepts as a particular business model that supports some specific customers.

[edit] The ASP model

The application software resides on the vendor's system and is accessed by users through a web browser using HTML or by special purpose client software provided by the vendor. Custom client software can also interface to these systems through XML APIs. These APIs can also be used where integration with in-house systems is required.

Common features associated with ASPs include:

• ASP fully owns and operates the software application(s)
• ASP owns, operates and maintains the servers that support the software
• ASP makes information available to customers via the Internet or a "thin client"
• ASP bills on a "per-use" basis or on a monthly/annual fee

The advantages to this approach include:

• Software integration issues are eliminated from the client site
• Software costs for the application are spread over a number of clients
• Vendors can build more application experience than the in-house staff
• Key software systems are kept up to date, available, and managed for performance by experts
• Improved reliability, availability, scalability and security of internal IT systems
• A provider's service level agreement guarantees a certain level of service
• Access to product and technology experts dedicated to available products
• Reduction of internal IT costs to a predictable monthly fee.
• Redeploying IT staff and tools to focus on strategic technology projects that impact the enterprise's bottom line

Some inherent disadvantages include:

• The client must generally accept the application as provided since ASPs can only afford a customized solution for the largest clients
• The client may rely on the provider to provide a critical business function, thus limiting their control of that function and instead relying on the provider
• Changes in the ASP market may result in changes in the type or level of service available to clients
• Integration with the client's non-ASP systems may be problematic

Evaluating an Application Service Provider security when moving to an ASP infrastructure can come at a high cost, as such a firm must assess the level of risk associated with the ASP itself. Failure to properly account for such risk can lead to:

• Loss of control of corporate data
• Loss of control of corporate image
• Insufficient ASP security to counter risks
• Exposure of corporate data to other ASP customers
• Compromise of corporate data

Some other risks include failure to account for the financial future of the ASP in general, i.e. how stable a company is and if it has the resources to continue business into the foreseeable future. For these reasons Cisco Systems has developed a comprehensive evaluation guideline. This guideline includes evaluating the scope of the ASP's service, the security of the program and the ASP's maturity with regard to security awareness. Finally the guidelines indicate the importance of performing audits on the ASP with respect to:

• Port/Network service
• Application vulnerability
• ASP Personnel

Physical visits to the ASP to assess the formality of the organization will provide invaluable insight into the awareness of the firm.

[edit] History

In terms of their common goal of enabling customers to outsource specific computer applications so they can focus on their core competencies, ASPs may be regarded as the indirect descendants of the service bureaus of the 1960s and 1970s. In turn, those bureaus were trying to fulfill the vision of computing as a utility, which was first proposed by John McCarthy in a speech at MIT in 1961.

[edit] See also

• Software as a service
• Communication as a service
• Hosted service provider
• Business service provider
• Service level agreement
• Utility computing
• Outsourcing
• Multitenancy
• Secure virtual office
• Master managed service provider

A social network hosting service is a web hosting service that specifically hosts the creation of web-based social networking services, alongside related applications.

[edit] List of social network hosting services

• Ning
• KickApps
• OneSite
• Mzinga
• Prospero
• Pluck
• DZOIC
• Small World Labs
• Crowdvine
• The Village
• IGLOO
• Soceeo.com
• Lithium Technologies
• WackWall
• Intuu
• Neighborhood America
• SocialGO
• Insoshi
• TabUp
• Flux
• Big Tent
• BricaBox

A file hosting service, online file storage service, or online media center is an Internet hosting service specifically designed to host static content, typically large files that are not web pages. Typically they allow web and FTP access. They can be optimized for serving many users (as is implied by the term "hosting") or be optimized for single-user storage (as is implied by the term "storage"). Related services are video sharing, virtual storage and remote backup.

[edit] Uses

[edit] Software file hosting

Authors of Shareware, Freeware and Open Source/Free software often use file hosting services to serve their software. The inherent problem with free downloads is the huge bandwidth cost. These hosts also offer additional services to the authors such as statistics or other marketing features.

[edit] Personal file storage

Personal file storage services are aimed at private individuals, offering a sort of "network storage" for personal backup, file access, or file distribution. Users can upload their files and share them publicly or keep them password-protected.

Prior to the advent of personal file storage services, off-site backup services were not typically affordable for individual and small office computer users.

Sometimes people prefer hosting their files on a publicly accessible HTTP server. In this case, they generally choose paid hosting, and use their hosting for this purpose. Many free hosting providers do not allow the storage of files for non-website-related use.

[edit] Content caching

Content providers who potentially encounter bandwidth congestion issues may use services specialized in distributing cached or static content. It is the case for companies with a major Internet presence.[1]

[edit] Storage

Most online file storage services offer space on a per-gigabyte basis, and sometimes include a bandwidth cost component as well. Usually these will be charged monthly or yearly. Some companies do offer the service for free, relying on advertising revenue. Some hosting services do not place any limit on how much space your account can consume. Some services require a software download which makes files only available on computers which have that software installed, others allow users to retrieve files through any web browser. With the increased inbox space offered by webmail services, many users have started using their webmail service as an online drive. Some sites offer free unlimited file storage but have a limit on the file size.

Increasingly, organizations are recognizing the benefits of co-locating their mission-critical equipment within a data centre. Colocation is becoming increasingly popular because of the time and cost savings a company can realize as a result of using shared data centre infrastructure. Significant benefits of scale (large power and mechanical systems) result in large colocation facilities, typically 5,000-10,000 m² (50,000 to 100,000 square feet). With IT and communications facilities in safe, secure hands, telecommunications, Internet, ASP and content providers, as well as enterprises, enjoy less latency and the freedom to focus on their core business.

Additionally, customers reduce their traffic back-haul costs and free up their internal networks for other uses. Moreover, by outsourcing network traffic to a colocation service provider with greater bandwidth capacity, web site access speeds should improve considerably.

Major types of colocation customers are:

• Web commerce companies, who use the facilities for a safe environment and cost-effective, redundant connections to the Internet
• Major enterprises, who use the facility for disaster avoidance, offsite data backup and business continuity
• Telecommunication companies, who use the facilities to interexchange traffic with other telecommunications companies and access to potential clients

Most network access point facilities provide colocation.

[edit] Services offered

Most colocation centres offer different types of services to customers ranging from dedicated suites/rooms or cages to smaller racks or partial racks. Some colocation centres also offer some degree of service level agreements to support a wide range of computer and network related services, for example, server reboots, hardware replacements and software updates.

There are a few key differences between a dedicated server and colocation servers. Dedicated servers tend to be owned and rented out, while a colocation server is one that the client owns.

Some colocation centres feature a "meet-me-room" where the different carriers housed in the centre can efficiently exchange data. Most peering points sit in colocation centres. These sites are often used for web hosting. Most colocation centres have high levels of physical security and multiple redundant power and humidity/air-conditioning systems.

Confusingly, one company can operate a colocation centre, another can provide the bandwidth, whereas a third company would rent a cage inside the centre, renting out racks to hosting providers which would rent the servers themselves to actual clients. Any and all of those companies will claim ownership of the facility and will feature photos and descriptions of it on their web sites. At the actual physical location various ID cards with various logos will be present, including those of the company that built/rents/owns the actual building.

[edit] File mirroring

In 2006, Sharebee started a new type of file hosting site, known as a file mirror, file distribution or file spreading engine. These services allow users to upload their file to the hosting servers. The user's file is then distributed to multiple web hosts without using the user's bandwidth. For more information, see Mirror (computing).

[edit] One-click hosting

One-click hosting generally describes web services that allow internet users to easily upload one or more files from their hard drives (or from a remote location) onto the one-click host's server free of charge.

Most such services simply return a URL which can be given to other people, who can then fetch the file later on. As of 2005 these sites have drastically increased in popularity, and subsequently, many of the smaller, less efficient sites have failed. Many internet forums exist in order to share such links; this type of file sharing has, to a degree, taken over from P2P filesharing services[2].

The sites make money through advertising or charging for premium services such as increased downloading capacity, removing any wait restrictions the site may have or prolonging how long uploaded files remain on the site. Many sites implement a CAPTCHA to prevent automated downloading.

[edit] Comparison of notable file hosting services

The table below presents a comparison of notable file hosting services used for file sharing.

Web Host	Language	Storage size	Max. file size	Direct access[3]	Traffic/bandwidth limit	File expiration[4]	Misc. notes	Remote Uploading?	Ability to delete files?	Table-entries (Added or Revised) Date (YYYY-MM-DD)
Live Mesh	EN	&0000000000000005.0000005 Gb (free)	?	Yes	none	none	Synchronizes files between PC, Mac, and Mobile devices. Developer platform in CTP will allow sync for any feed based data across user devices via REST/Atom protocol.	Yes	Yes	2008-12-4
Dropbox	EN	&0000000000000002.0000002 GB (free)	Unlimited (via client application), 350 MB (via web interface)	Yes	?	?	Primarily as backupservice but websharing possible.	?	Yes	2008-10-30
Box.net	EN	1 GB (free), 5-15 GB (non-free)	&0000000000000025.00000025 MB (free), 1GB (non-free)	?	10 GB (free), Unlimited (non-free)	?	1 GB (free), 5GB-15GB+ (non-free)	?	Yes	?
FileFront	EN	&0000000000001000.0000001,000 MB	?	Yes	?	6 months of inactivity	Premium advert-free service available via FastPass. Limited to video gaming files.	?	Yes	?
Files.Mail.ru	EN	&0000000000001000.0000001,000 MB	?	Yes	no limit	30 days	Storage size is 10GB per user after sign up.	No	Yes	2008-09-17
MediaFire	EN	Unlimited	100 MB	Yes	none	30/60 days of inactivity[5]	Resuming of interrupted downloads possible.	Partial Only for pro users	Yes	?
Megaupload	EN, DE, FR, IT, ...	50 GB (free), 1 TB (non-free)	1024 MB (non-paying users), no size limit (premium users)	No, CAPTCHA, wait 45 s (25 s with free registration)	Traffic limit, no parallel downloads (non-paying users), unlimited downloads (premium users)	90 days of inactivity for free users	For users with a cost-free account the waiting time is 25 s and the file expiration period is 90 days of inactivity. Less restrictions for premium accounts. Premium accounts can store up to 1 TB.[6]	Partial Only for premium users	Yes	2008-12-26
RapidShare	EN/DE	500 GB (premium users)	&0000000000000200.000000200 MB (non-paying users), 2000 MB (premium users)	No, waiting time (depends on file size)	bandwidth limited to 500 kbit/s (non-paying users), a premium account allows the download of 2.66 GB per day	90 days of inactivity (non-paying users), none (premium users)	No captchas anymore for non-paying users, but severely limited bandwidth.	Yes 50 running jobs at a time for Free & premium users	Yes	2008-12-26
Amazon S3	EN	Unlimited -uses Amazon S3	5GB file size per bucket in S3, some vendors such as SecoBackup support over 5GB files	Yes	Amazon S3 limits	None, pay for storage each month		No	Yes	2009-01-27
SendSpace	EN	-	&0000000000000300.000000300 MB (free), 1.5 GB (premium)	Yes	?	21 days of inactivity	?	Yes SendSpace Wizard	Yes	?
SoundCloud	EN	Unlimited	?	Yes	{{{1}}}	No	Music file hosting only. Free accounts are limited to 5 tracks/month.	Yes through API	Yes	2008-11-28
SteekR	EN, FR, DE, IT, BR	&0000000000000001.0000001 GB (free)	?	Yes	none	none	Total storage space limited to 1 GB for non-paying users.	Yes SteekR DriveDrive	Yes	?
YouSendIt	EN	up to 6 GB (non free)	&0000000000000100.000000100 MB (free)	Yes	100 downloads per file for free registered (YouSendIt Lite) users. 3 downloads for unregistered users.	7 days	?	?	?	?
Wuala	EN/DE/PT/FR ...	1 GB	none	Yes	none	none	You can get unlimited space for free by trading storage. Has a strong Social Network component.	Yes	Yes	2009-01-05
Web Host	Language	Storage size	Max. file size	Direct access	Traffic/bandwidth limit	File expiration	Misc. notes	Remote Uploading?	Ability to delete files?	Table-entries (Added or Revised) Date (YYYY-MM-DD)

[edit] See also

• Remote backup service

A remote, online, or managed backup service is a service that provides users with an online system for backing up and storing computer files. Managed backup providers are companies that provide this type of service.

Online backup systems are typically built around a client software program that runs on a schedule, typically once a day. This program collects, compresses, encrypts, and transfers the data to the remote backup service provider's servers. Other types of product are also available in the market, such as remote continuous data protection (CDP).

Providers of this type of service frequently target specific market segments. High-end LAN-based backup systems may offer services such as near-realtime transaction-level replication or open file backups. Consumer online backup companies frequently have beta software offerings and/or free-trial backup services.

[edit] History

Most online/remote backup services came into existence during the heyday of the dotcom boom in the late 1990s with the exception of a few early pioneers like industry originator Rob Cosgrove, CEO of Remote Backup Systems. While the initial years of these service providers were about capturing market share distributed among the top few providers, the large industry players took cognizance of the importance and the role that these online backup providers were playing in the web services arena and M&A activity has became quite predominant in the last few years. Today, most service providers of online backup services position their services using the SaaS (software as a service) strategy and its relevance is predicted to increase exponentially in the years to come as personal and enterprise data storage needs rise. The last few years have also witnessed a healthy rise in the number of online backup providers with them existing independently as also as part of a business unit of a larger industry behemoth.

[edit] Typical features

Opened File Backup

The ability to back up files that are extensively opened, such as Outlook files (*.pst) or SQL database files can be useful. Such ability allows IT administrators to run back up jobs any time of the day, not requiring setting aside server maintenance time. Most enterprise online backup products support an add-on for this. Higher-end products support this natively.

Multi-platform

A Multi-platform backup service can back up multiple platforms such as the various flavors of Windows, Macintosh, and Linux/UNIX.

Multi-site

A feature of some services is the capability to back up the primary site data plus remote offices and branch offices in a relatively seamless manner.

Continuous backup - Continuous Data Protection CDP 

Allows the tool to back up continuously or on a predefined schedule. Both methods have advantages and disadvantages. Most backup tools are schedule-based and perform backups at a predetermined time. Some services provide continuous data backups which are used by large financial institutions and large online retailers. However, there is typically a tradeoff with performance and system resources.

Online Access to files

Some services allow you to access your backed up files via a normal web browser. Many tools do not provide this type of functionality.

Data Compression

typically data will be compressed with a lossless compression algorithm to minimize the amount of bandwidth used.

Differential Data Compression

A way to further minimize network traffic is to transfer only the binary data that has changed from one day to the next, similar to the open source file transfer tool Rsync. More advanced network backup tools use this method rather than transfer entire files.

Data Encryption

Encryption of data during transmission to vendor and encryption when stored at vendor

Bandwidth Usage

User selectable to use more or less bandwidth at various times

[edit] Cost factors

Online backup services are usually priced as a function of the following things:

1. The total amount of data being backed up.
2. The number of machines covered by the backup service.
3. The maximum number of versions of each file that are kept.
4. Data retention and archiving period options

Some vendors limit the number of versions of a file that can be kept in the system. Some services omit this restriction and provide an unlimited number of versions. Add-on features (plug-ins), like the ability to back up currently open or locked files, are usually charged as an extra, but some services provide this built in.

Most remote backup services reduce the amount of data to be sent over the wire by only backing up changed files. This approach to backing up means that the customers total stored data is reduced. Reducing the amount of data sent and also stored can be further drastically reduced by only transmitting the changed data bits by binary or block level incremental backups. Solutions that transmit only these changed binary data bits do not clog bandwidth by transmitting the same file data over and over again if only small amounts (ie a date change or different address in a word document)

[edit] Advantages of remote backup

Remote backup has advantages over traditional backup methods:

• Remote backup does not require user intervention. The user does not have to change tapes, label CDs or perform other manual steps.
• Remote backup maintains data offsite. Perhaps the most important aspect of backing up is that backups are stored in a different location from the original data. Traditional backup requires manually taking the backup media offsite.
• Unlimited data retentions
• Data storage abroad could be an advantage too.
• Some remote backup services will work continuously, backing up files as they are changed.
• Most remote backup services will maintain a list of versions of your files.
• Most remote backup services will use a 128 - 448 bit encryption to send data over unsecured links (ie internet)
• A few remote backup services can reduce backup by only transmitting changed binary data bits

[edit] Disadvantages of remote backup

Remote backup has some disadvantages:

• Depending on the available network bandwidth, the restoration of data can be slow. Because data is stored offsite, the data must be recovered either via the Internet or via tape or disk shipped from the online backup service provider.
• Some backup service providers have no guarantee that stored data will be kept private - for example, from employees. As such, most recommend that files be encrypted before storing or automate this this process.
• It is possible that a remote backup service provider could go out of business or be purchased, which may affect the accessibility of one's data or the cost to continue using the service.
• If encryption password is lost, no more data recovery will be possible. However with managed services this should not be a problem.

[edit] See also

• Off-site data protection - The practice of sending data off-site for safe keeping, but not necessarily using a remote backup service.
• List of backup software (includes Managed backup providers)
• List of online backup services

A game server is a remotely or locally run server used by game clients to play multiplayer games. Most video games played over the internet operate via a connection to a game server.

[edit] Game server hosting

Game server providers (GSPs) are companies that lease dedicated game servers. Gaming clans will often lease one or more servers for their chosen game, with members of the clan contributing to the server rental fees.

Game server providers often offer web based tools to help control and configure the individual game servers and most allow those that rent/lease to modify the games being leased.

[edit] Types of game servers

Game servers can be classified as listen servers and dedicated servers. Listen server refers to a situation in which the server typically runs in the same process as the game client, allowing a player to both host and participate in the game. As a side effect, the server is usually terminated when the client is. Listen servers are operated mostly by individuals, often in LAN Party situations rather than over the internet, and usually with a lower number of players due to the increased processing and bandwidth requirements associated with operating both server and client simultaneously on the same machine. Dedicated servers are servers which run independently of the client. Such servers may be run by individuals, but are usually run on dedicated hardware located in data centers, providing more bandwidth and dedicated processing power. Dedicated servers are the preferred method of hosting game servers for most PC-based multiplayer games. Massively multiplayer online games run on dedicated servers usually hosted by the software company that owns the game title, allowing them to control and update content. In many cases they are run on clustered servers to allow for huge environments and large player counts.

A DNS hosting service is a service that runs Domain Name System servers. Most, but not all, domain name registrars include DNS hosting service with registration. Free DNS hosting services also exist. Almost all DNS hosting services are "shared"; except for the most popular Internet sites, there is no need to dedicate a server to hosting DNS for a single website. Many third-party DNS hosting services provide Dynamic DNS.

DNS hosting service is better when the provider has multiple servers in various geographic locations that minimize latency for clients around the world.

DNS can also be self-hosted by running DNS software on generic Internet hosting services.

[edit] Free DNS

A number of sites offer free DNS hosting, either for second level domains registered with registrars which do not offer free (or sufficiently flexible) DNS service, or as third level domains (selection.somedomain.com). These services generally also offer Dynamic DNS. Free DNS typically includes facilities to manage A, MX, CNAME, TXT and NS records of the domain zone.[citation needed]In many cases the free services can be upgraded with various premium services.

Free DNS service providers can also make money through sponsorship. The majority of modern free DNS services are sponsored by large providers of a telecommunication services.[citation needed]

Frequently their servers are worldwide located to provide high speed of work, and also high reliability.[citation needed]

[edit] See also

• Domain Name System, domain name
• Dynamic DNS
• Fast-flux DNS

An email hosting service is an Internet hosting service that runs email servers.

Email hosting services usually offer premium email at a cost as opposed to advertising supported free email or free webmail. Email hosting services thus differ from typical end-user email providers such as webmail sites. They cater mostly to demanding email users and Small and Mid Size (SME) businesses, while larger enterprises usually run their own email hosting service. Email hosting providers allow for premium email services along with custom configurations and large number of accounts. In addition, hosting providers manage user's own domain name, including any email authentication scheme that the domain owner wishes to enforce in order to convey the meaning that using a specific domain name identifies and qualifies email senders.

Most email hosting providers offer advanced premium email solutions hosted on dedicated custom email platforms. The technology and offerings of different email hosting providers can therefore vary with different needs. Email offered by most webhosting companies is usually more basic standardized POP3 based email and webmail based on open source webmail applications like Horde or Squirrelmail. Almost all webhosting providers offer standard basic email while not all email hosting providers offer webhosting.

[edit] Implementation

For a technical overview of how email hosting services are engineered you can read about email hubs.