I'm referring to Microsoft's moves in the past year to release their compiler and other parts of the .NET toolchain (and Xamarin) as MIT-licensed open-source projects (moves the company wasn't forced to make). Even though the language itself has been an open standard for some time, the C# ecosystem was very different a few years ago than it is in 2016.
I think however that this may be one of those cases when perception is stronger than reality: perception of what Microsoft is and what Java is.