Adobe® Flex ™ becomes OpenSource !!!

Adobe announces plans to open Flex source code under the Mozilla Public License (MPL). This includes not only the ActionScript sources of the Flex SDK components, which were available in the form of source code in the SDK, but also includes Java sources for ActionScript and MXML compilers, ActionScript debugger, and the main ActionScript SDK libraries

The Flex SDK contains all the components you need to create Flex applications running in any browser on Mac OS X, Windows, and Linux.

Details here and here .