Before AJAX, Flash is historically the oldest RIA technology. Flash was developed in the 1990s by Macromedia and acquired by Adobe in 2005. In contrast to AJAX, Flash is a real RIA technology. A Flash Player is required for playback of Flash applications in a browser, which is available free from Adobe. Some years ago, Flash was used exclusively for playback of multimedia content or animation. Today even more complex browser-based applications can be written object-oriented programming language ActionScript Adobe.
Flash offers the opportunity to develop different types of applications, but it basically works only frame-based. RIAs and hence Silverlight and JavFX, Java applets make many rich opportunities, but also problems in everyday usage, which did not exist in conventional Web site. A RIA is embedded in an HTML page. Will now navigate within the RIA, you can individual pages as bookmarks in the browser does not save, because the HTML page that is in the address bar of the browser has not changed. Microsoft will fix this problems with Silverlight 3. A further difficulty arises for the search engine optimization of an RIA. So, the conventional crawler can index the contents of a RIA limited.
The contents of a RIA application are not defined and therefore not for the search engines to read page in the source code of the HTML. At least in the area of the indexing of RIA content, try ways to quickly find the operators of search engines. It is clear that the use of RIAs is increasing more and more on the Internet and also the market-dominant companies like Google as soon as possible must adapt to the new situation. Even Microsoft wants to improve search engine optimization with the new version of Silverlight 3. A website should use only for multimedia or interactive needs of RIA technologies. As basic HTML and CSS are definitely preferable.