A web desktop or webtop is a desktop environment embedded in a web browser or similar client application. A webtop integrates web applications, web services, client–server applications, application servers, and applications on the local client into a desktop environment using the desktop metaphor. Web desktops provide an environment similar to that of Windows, Mac, or a graphical user interface on Unix and Linux systems. It is a virtual desktop running in a web browser. In a webtop the applications, data, files, configuration, settings, and access privileges reside remotely over the network. Much of the computing takes place remotely. The browser is primarily used for display and input purposes.
The terms "web desktop" and "webtop" are distinct from web operating system, a network operating system such as TinyOS or distributed operating system such as Inferno. In popular use, web desktops are sometimes referred to incorrectly as web operating systems or simply WebOS.
In the context of a web desktop, the term Webtop was first introduced by the Santa Cruz Operation (SCO) in 1994 for a web-based interface to their Unix operating system. This application was based on the provisional application entitled "The Adaptive Internet Protocol System" filed Nov. 13, 1997, serial number 60/065,521 and is the U.S. patent for the technology used in the Tarantella Webtop. Andy Bovingdon  and Ronald Joe Record, who both explored the concepts in different directions, are often credited as the inventors. The initial SCO Webtop, developed by Record, utilized a Netscape Navigator plugin to display applications in a browser window via TightVNC. A trademark application for "SCO Webtop" was filed with the U.S. Patent and Trademark Office on November 8, 1996. In order to avoid confusion with the more complex technology incorporated into the Tarantella Webtop it was abandoned on December 24, 1997 by The Santa Cruz Operation.
The first SCO Webtop releases were part of SCO Skunkware before being integrated into SCO OpenServer version 5 and UnixWare 7. Tarantella was subsequently purchased by Sun Microsystems and integrated into their Sun Secure Global Desktop.
Byte magazine referred to the Webtop as a NUI (Network User Interface).
More recently, Google released an operating system for web connection called Chrome OS and several 11-12" netbooks from Acer and Samsung have implemented the system. It is thought to represent a useful fraction (~10%) of the current (2012) netbook sales.
- A personalized desktop on every supported client device
- Access your desktop anywhere there is a supported client device
- Session management
- Server-side session management allows roaming users to access restored sessions from anywhere
- Software management
- Ensures all users are running the same current versions of all applications
- Updates and patches need only be applied to the server - no need to update multiple clients
- No need for software to distribute software over the network
- Less prone to typical attacks, viruses, worms, unpatched clients, vulnerabilities
- Sensitive data stored on secure servers rather than scattered across multiple potentially unprotected and vulnerable clients (e.g. smart phones and laptops)
- Encrypted transmission of all data between server and clients (e.g. https)
- Software Management features (above) accommodate quick and easy application of security advisories on server side
- Webtop administrator can control which applications and data each user is allowed to access
- High availability
- From a single device access Windows, UNIX, Linux, and Mainframe applications, all at the same time
- Minimal hardware requirements for client devices (except for rendered technologies such as Flash/Flex/SilverLight)
- Less downtime - robust server system more easily protected and less likely to fail than multiple client desktops
- Fault tolerance - if a client device fails for any reason simply replace it with any other supported client device without loss of data, configuration, preferences, or application access
- Because all data is transferred over the internet, it might be possible for a cracker to intercept the connection and read data. Although with the use of https 256-bit encryption and access control lists, this can be easily safe-guarded.
- When using a web desktop the whole code used for visualization (.js/.css files, Flash player files, etc.) needs to be transferred to the local computer, so that it can be displayed. Further, network latency or congestion can intermittently slow webtop activity. Offline application storage can mitigate this issue.
- Application features
- Some webtop delivered applications may not contain the full feature set of their traditional desktop counterparts
- Network Access
- Web desktops require access to a network. If the client device is misconfigured or the network is unreachable then the web desktop is unavailable.
- Controlled access
- In some webtop implementations and deployments a user's access to some applications and data can be restricted. This is also considered an advantage of webtops but can be viewed as a drawback from the user's perspective.
- Central control
- The normal webtop user is not able to install additional applications or update existing applications. Updates typically must be performed by an administrator on the server side. Webtop users are dependent upon the webtop administrator whereas in the traditional desktop environment the user can fix and/or break the system by installing new software or updates. This can also be seen as an advantage for webtops.
Comparison of web desktops 
The following tables compare general and technical information for a number of web desktops.
|Name||Browser support||Developer||Engine||Free||License||3rd party applications||Productivity Suite||Graphical user interface||Downloadable to Web server||Still Active|
|appFlower||IE6/7/8, Firefox3/4/5, Safari, Opera, Chrome||AppFlower ApS||appFlower based on PHP + AJAX||No||Open Source: GPLv3||Yes||Yes||Customizable||Yes||Yes
|eyeOS||IE7/8, Firefox3, Safari, Opera, Chrome||eyeOS Team||PHP + AJAX||No||Proprietary||Yes||Yes||Customizable||Yes||Yes|
|G.ho.st||IE6+, Firefox2+, Safari. Partial: Chrome & Opera||Ghost Inc ("G.ho.st")||Flash + AJAX (mobile version is WAP)||No||Proprietary||Yes||Yahoo! Zimbra, Zoho, Google Docs, ILoveIM||Windows-like||No||No|
|Glide OS||IE7, Firefox 3, Safari, Chrome||TransMedia||HTML5||Yes (30 GB limit)||Proprietary||From Glide Community||Glide Write, Glide Presenter, Glide Crunch, Photo Editor, Email||Mac+Windows-like||No||Yes|
|Nivio||IE7, IE8, Google Chrome, FF 4||Sachin Dev Duggal, Saurabh Dhoot||In development||No||Proprietary||Yes||Yes||Windows||No||Yes|
|Online OS||FF 1.5 and higher, IE7||iCUBE Network Solutions||Java + Ajax||Yes||Proprietary||Yes||Yes||Windows-like||No||Yes|
|Oracle Secure Global Desktop||Any browser with a JRE||Oracle||AIP||No||Proprietary||Yes||Yes||Customizable||No||Yes|
|VMware View||IE, Firefox, Safari, Opera, Chrome||VMware||PCoIP, RDP, HTML5||No||Proprietary||Yes||Yes||Customizable||No||Yes|
|SkyDesktop||Firefox, Chrome, Safari, Opera, IE||InfoStreet||Python + Ajax||Yes||Proprietary||Yes||StreetSmart, Google Apps||Customizable||No||Yes|
See also 
- Comparison of remote desktop software
- Online office suite
- Rich Internet application
- Virtual Network Computing
- Web operating system
- Hosted desktop
- US patent 6,104,392, Shaw , et al., "Method of displaying an application on a variety of client devices in a client/server network", issued 2000-08-15
- Andrew J Bovingdon presented a Human Computer Interaction poster on the subject of Webtops at WWW2 in Chicago, 1994 entitled "Adding a new dimension to the desktop", http://web.archive.org/web/20041231084638/http://archive.ncsa.uiuc.edu/SDG/IT94/Agenda/Posters-received.html
- The Santa Cruz Operation Technical White Paper, Tarantella --The Universal Application Server, July, 1997
- See uspto.gov, click on "Trademarks -> Search TM Database", and perform a Basic search for "Webtop". The only earlier occurrences in both the Patent and Trademark databases are for systems unrelated to a web desktop context.
- SCO Skunkware Release Notes
- "Sun Microsystems Completes Tarantella Acquisition". Associated Press. 2005-07-13. Retrieved 2008-04-04.
- Web Application
- How offline application cache works
- SCO Tarantella Offers New Twist On an Old Thin-Client Dance, "Network Computing Magazine", Mark Andrew Seltzer, January 24, 2000
- Ditch That Desktop for a Webtop, PC World, October 16, 2000
- SCO Company History, Operating System Documentation Project
- SCO revamps UnixWare with Linux features, CNET News.com, February 23, 1999
- SCO Showcases Latest In Network Computing for Real-World Environments, Network Computing News, April 29, 1997