Microsoft .NET now Open Source?

This is a turn up for the books. Who would have thought this would even have been a option a few years back. Microsoft is open sourcing .NET, making the source available on GitHub, and even plans to make the framework cross platform to run on Linux and Mac – more here.

One can only speculate that they feel pressured to do this for .NET to stay relevant, and/or to expand it’s usage to other platforms outside of Windows? Given the accelerating trend to deploy to the cloud on virtualized platforms (in most cases on OSes almost certainly not to be Microsoft Windows), maybe Microsoft sees this as a strategic move for them to keep their development framework an option in this changing landscape?