Adobe Flex is a cross-platform, based on Macromedia flash software, comprehensive, development framework, an application development tool and solution for developing and delivering Rich Internet Applications (RIAs) within an enterprise and across the web to improve interactivity of the web. Applications created using flex are highly expressive, of high-performance and are compatible with all operating system and web browsers. Flex programmers, flex developers can download the free Flex SDK available online to work with Flex applications.