[alecdbrooks]

>Try incorporating some java code in a ruby project, however. No possible way that is going to fly.

I don't think this example is convincing. There are too many languages to expect arbitrary pairings to combine well. (Not to mention the fact that googling "java ruby" returns JRuby, which apparently lets you do just what you describe.)

I do agree with your last point: Even when we look at similar languages, like Python and Ruby, we don't declare one a winner, generally.