Last month, I blogged about Adobe Flex going open source. It seems Microsoft has taken notice, and is making some of Silverlight available as open source. Microsoft is also releasing the Dynamic Language Runtime (DLR) and IronPython on CodePlex under the Microsoft Permissive License. This allows developers and users to view, modify and redistribute source code for either commercial or non-commercial purposes, and also to charge a license fee for any code they’ve added to the software.
A DLR based version of Ruby, called IronRuby, is also in the works and will be included in a future release of Silverlight.