While choosing the most appropriate RIA technology for a project, we should consider several factors:

1. the reach (% of users who will be able to get the RIA experience with their installed browser and plug-ins)
2. the availability of open source vs. commercial products
3. the company’s internal knowledge
4. the development time (time to market)
5. the community and support infrastructure

In addition to the above factors, that we can define as “supporting considerations” to the process of choosing the most appropriate RIA technology, we should consider a 6th factor which consists of the “intimate” suitability of a RIA technology to manage:

- Users interaction
- Rich media content

At Comtaste, we have defined the following chart to describe the positioning of 6 different RIA technologies respect the 2 above mentioned parameters (each measured in terms of several features): Ajax, Adobe Flex, Java FX, Lazlo, Microsoft Silverlight 1.1 and XUL .

The chart has been named “the RIA domain” because it represents, like for a mathematical function, the area within which an application can be defined as a Rich Internet Application. It corresponds to our personal feeling and experience as RIA developers.

This chart has been included in the slides presented by Marco Casario at the Web 2.0 Expo of Berlin. The complete set of those slides can be found here.