<flame war ahead>
For those not adicted to slashdot, see here http://news.slashdot.org/story/15/02/04/0332238/microsoft-open-sources-coreclr-the-net-execution-engine .
Licenced under MIT https://github.com/dotnet/coreclr/blob/master/LICENSE.TXT, plus an additional patents promise https://github.com/dotnet/coreclr/blob/master/PATENTS.TXT.
If Microsoft continues to go in the direction of the OSS as before, I suspect we just might benefit from some good quality components as individual services on a completelly open source stack.