Rich Internet Application

A Rich Internet Application (RIA) is a Web application that has many of the characteristics of desktop applications, typically delivered either by way of a site-specific browser, via a browser plug-in, independent sandboxes, or virtual machines. Adobe Flash, Java, and Microsoft Silverlight are currently the three most common platforms, with penetration rates around 99%, 80%, and 54% respectively (as of July 2010). Although new Web standards have emerged, they still use the principles behind RIAs.

Users generally need to install a software framework using the computer's operating system before launching the application, which typically downloads, updates, verifies and executes the RIA. This is the main differentiator from JavaScript-based alternatives like Ajax that use built-in browser functionality to implement comparable interfaces. While some consider such interfaces to be RIAs, some consider them competitors to RIAs; and others, including Gartner, treat them as similar but separate technologies.

RIAs dominate in online gaming as well as applications that require access to video capture (with the notable exception of Gmail, which uses its own task-specific browser plug-in). Web standards such as HTML5 have developed and the compliance of Web browsers with those standards has somewhat improved. However, the need for plug-in based RIAs for accessing video capture and distribution has not diminished, even with the emergence of HTML5 and JavaScript-based desktop-like widget sets that provide alternative solutions for mobile Web browsing.

History

The term "rich Internet application" was introduced in a white paper of March 2002 by Macromedia (now merged into Adobe), though the concept had existed for a number of years earlier under names such as:

• Remote Scripting, by Microsoft, circa 1999
• X Internet, by Forrester Research in October 2000
• Rich (Web) clients
• Rich Web application

Design, measurement, performance

Rich Internet applications use a distributed-function model rather than the simple thin-client–server model..

Flash, Silverlight and Java are browser plug-ins that attempt to reduce reliance on network/server communications. All three products rely on pre-installed application frameworks. Pages use such frameworks to limit the amount of data loaded to only what is necessary to display the page. The browser plug-in is only downloaded once, and does not need to be re-downloaded every time the page is displayed; This reduces page load time, bandwidth requirements, and server load.

Characteristics

RIAs present indexing challenges to search engines, but Adobe Flash content is now at least partially indexable.

Security can improve over that of application software (for example through use of sandboxes and automatic updates), but the extensions themselves remain subject to vulnerabilities and access is often much greater than that of native Web applications. For security purposes, most RIAs run their client portions within a special isolated area of the client desktop called a sandbox. The sandbox limits visibility and access to the file-system and to the operating system on the client to the application server on the other side of the connection. This approach allows the client system to handle local activities, calculations, reformatting and so forth, thereby lowering the amount and frequency of client-server traffic, especially as compared to the client-server implementations built around so-called thin clients.

See also

• HTML5
• List of rich Internet application frameworks
• PIGUI

External links

• Accessible Rich Internet Applications (WAI-ARIA) 1.0 - W3C Working Draft 15 December 2009
• The W3C Rich Web Clients Activity