Adobe have announced plans to open source the Flex platform in full under the open source Mozilla Public License (MPL) by the end of 2007.
Adobe have surprised many today by announcing plans to release their Flex SDK as open source later this year. The Flex SDK comprises of a number of technologies including the Flex Framework, Flex Components, and ActionScript 3.0 libraries - they will be open sourced under a Mozilla Public License.
While it's rival OpenLaszlo has been free and open source since the release of Flex 1.0, Adobe has said today that it will expand on the source code already released under the Flex SDK so developers can freely download, extend and contribute to extending the Flex compiler, components, and application framework.
From June 2007 Adobe will be providing access to their Flex bug database and posting daily builds of the Flex SDK. December 2007 should see the release of Flex 3, code named "Moxie", Adobe intends to provide access to the Flex Subversion repository once the release has occured.
Adobe Labs have set up an FAQ for developers interested in contributing to the project.
Both the Flash Player and Adobe's new runtime Apollo are to remain closed source as are Flex Data Services and premium components like Charting.
It's interesting to see what affect this will have on the release of Microsoft's new browser plugin Silverlight.