> I think marrying yourself to a proprietary language like C# is a mistake, not because of any particular C# language feature, but because it's yet another prod

> I think marrying yourself to a proprietary language like C# is a mistake, not because of any particular C# language feature, but because it's yet another product of Microsoft's extreme case of Not-Invented-Here Syndrome That's really inaccurate. Mono aside, C# came up with quite a few innovations of its own, and I'm saying as a 15 year veteran Java developer who would love to see some of these be added to Java (at least we're getting closures next year). Also, learning C# will teach you a lot of constructs and concepts that will be readily available in other languages such as Java, Kotlin, Ceylon or Scala (and to some extent, even Haskell). The "proprietary, NIH, blah blah I hate Microsoft" nonsense belongs on slashdot, not here.