[oaiey]

You are definitely right with the library shism (Silverlight to blame). But, on the other hand, it also shows how adaptive this environment is. And not only the language but also the base class library, which independent of actual Factorings (like Silverlight, WinRT, Framework, Mono whatever) allowed a familiar environment to program in.

Java had also its moments (mobile Java, ee java, Android/Google Java, or Microsoft J++ (which btw. Was also Anders doing). About Python I just say 2/3 and let us not start with JavaScript. Languages and class libraries evolve and adapt. Not always to the better but they do and should.

[iainmerrick]

Hmm, I don't think Java has had it nearly as bad historically (possibly apart from the old mobile Java profiles, which I agree were quite painful). Any code using the core classes (math, collections, basic I/O) would always work fine on any JVM, including Android. Porting pure Java code to Android has always been very easy, as it should be.

Whereas I've found with C# that even perfectly innocuous-looking functions would be mysteriously unavailable in Silverlight, say. It has been very hard to pick a C# library subset that's both portable and useful, and Microsoft seem to have taken an awfully long time to sort that out.

[oaiey]

I ported huge amounts of code to .NET Core and it was effortless. It always depends which API your code uses. I think that is similar to your Java experience.

The Core API factoring was focused to remove deprecated API. When not using "deprecated" framework API, the porting is pretty easy.