Historical open source movements

Microsoft began to pave the way in open source as far back as 2003, when the first moves were made in order to adopt GPL Licensing on some products, the most noticeable being the effort to standardize the .NET Framework platform in general and the C# Language in particular.

Actually, it was soon approved as a standard by ECMA (ECMA-334) and ISO (ISO/IEC 23270:2006).

Later on, the Mono Project (Xamarin) (https://en.wikipedia.org/wiki/Mono_(software)), which is now part of Microsoft, provided versions of .NET capable of running in Linux and MacOS. This was probably the first serious attempt to make C# universal. The Mono licensing model was clearly open (http://www.mono-project.com/docs/faq/licensing/), although their IDE was not (Xamarin Studio).

However, the acquisition of Xamarin by Microsoft brought even better news to developers, since now, clients of Visual Studio Community Edition could find Xamarin tools and libraries embedded in the IDE with all the value...