There are really several layers of issues to deal with in regards to the JVM. First, the JVM really IS NOT a great choice to build other languages on. It wasn'

There are really several layers of issues to deal with in regards to the JVM. First, the JVM really IS NOT a great choice to build other languages on. It wasn't designed for it; In fact before invokedynamic, it was nearly impossible. For all intents, building other languages on the JVM is a bad hack, regardless of how elegant ( or not ) the language syntax is. The amount of fuckery required is nearly unbelievable. Second, the JVM is owned by Oracle. It is technically 'open source' but Oracle has proven time and again to not only be against open source, but one could even support the position that they're actively hostile towards it. Ideally, the solution would be to invest engineering mind-share into creating a REAL VM that was designed to host many programming languages. Regardless of what you think of Microsoft, they got .Net correct in that their tooling infrastructure was built from the beginning with multiple programming languages sitting on top of the CLR ( and later the DLR ). The LLVM folks have been making some progress in this regard by way of VMKit, but personally I cannot understand why this issue doesn't get more mind-share. Python, Scala, Ruby, Clojure, Lua, etc would all benefit in the end.