http://blogs.msdn.com/hugunin/archive/2007/04/30/a-dynamic-language-runtime-dlr.aspx http://tirania.org/blog/ Microsoft is open sourcing some very nice pieces of technology. They have reimplemented Ruby, Python, Javascript, and OCaml as .NET languages. They have released their new dynamic language runtime (DLR), a sandboxing runtime called Silverlight, as well as the first two of those four languages, under the Microsoft Permissive License, which seems like a very open license. OCaml is provided free as in beer, but under a more restrictive license that might keep it out of Linux distros. Here is the Microsoft Permissive License. It is a short license that doesn't seem to have any weird strings attached. http://www.microsoft.com/resources/sharedsource/licensingbasics/permissivelicense.mspx This is a very significant gift to the open source community, and I don't see any indication of Trojans hiding inside.