Adobe Flex Builder is an amazing open source framework developed by Adobe for building impressive web applications that does not have any compatibility issue across browsers,desktops and Operating systems.The adobe flex builder uses Adobe Flash player for running web applications and adobe air for running desktop applications.

Flex provides a modern, standards-based language and programming model that supports common design patterns. MXML, a declarative XML-based language, is used to describe UI layout and behaviors, and the object-oriented ActionScript® 3.0 programming language is used to create client logic. Flex also includes a rich component library with more than 100 proven, extensible UI components for creating rich Internet applications (RIAs), as well as an interactive Flex application debugger.