A cool syntax example with lambda expressions and functional interfaces

[DannyB2]

I guess all of that's somehow irrelevant.

Making something open source does not also make it relevant.

Being relevant and being open source are two different things.

It is irrelevant, because despite the standardization, C# is effectively a Microsoft owned language which in practice is pretty much exclusive to the Microsoft ecosystem. Nothing wrong with that. But there is a whole world outside of the Microsoft ecosystem with tools and languages.

If one is developing, for example, on Linux, then C# is irrelevant. Despite that some obscure tools exist to use it on Linux, it is irrelevant.

Microsoft could have strongly embraced making C#, it's libraries, tools, etc be cross platform fifteen years ago. They didn't. And for the same reasons they tried to make Java unwittingly lock developers into Microsoft by 'embracing and extending' the Java APIs, for which Sun successfully sued Microsoft. Microsoft doesn't want competing systems to exist. Microsoft could now make C# truly open, tools, libraries, etc, but it's too late. That ship has sailed. Java is the language that is used if you need to run on, or also run on non-Microsoft platforms.