Ask HN: Why hasn't JVM become the defacto implementation for dynamic languages?
With recent dynamic language implementations on the JVM meeting or surpassing performance of the "native" VMs, why hasn't there been a move to have the JVM become the default implementation?
Jython is a great example. It's fast -- faster than CPython in a lot of cases, and it doesn't have the GIL. And it gets access to the full Java environment if it wants it, presumably including things like Clojure, JRuby, Scala, etc. where appropriate.
This seems like a win/win to me, yet there is almost no traction in this direction. I can think of a couple of reasons why this might be:
1. I'm wrong and Jython isn't actually any faster.
Even if it isn't faster, the better environment should make up for this.
2. Integration with Java land isn't that much of a benefit.
Having access to all of this stuff -- but not being forced to use it -- seems great to me. There's no real downside and lots of potential upside, including increased market penetration in enterprise environments.
3. The JVM won't benefit from dozens to hundreds of programmers from python/ruby/etc applying what they've learned in their respective languages to it.
Maybe this is a case of too many cooks in the kitchen. Linux seems to do well with the "shittons of developers working simultaneously" method of doing things, why can't the JVM?
Even if the language developers don't work on the JVM at all, so what? See points 1 and 2.
4. Lagging behind by a few versions (Jython is at what, 2.5.x?) is a bigger deal than I'm imagining.
This could be made up for within a year or 2 if languages committed to the JVM as their default implementation.
5. Non-perfect compatibility breaking lots of stuff
This is a major concern, right? It's not like Python3 isn't doing the same thing right now, or seemingly every version of Ruby doing the same thing. Oh wait, they do.
Maybe the JVM isn't the right vm to standardize on; maybe LLVM would be more appropriate. I don't know. What I do know is that it seems silly for a bunch of language designers to all be having a big case of NIH and writing their own vms and bytecode interpreters.
Thoughts?