So I checked out what's available and I narrowed it down to Jython and JRuby.
Jython pros:
- The Python language is pretty popular for games
- Looks pretty stable (they are up to version 2)
Jython cons:
- Library is 2.7mb, which is pretty big if I ever hope to sell any games to people on dial-up.
- The whitespace thing bugs me. Are brackets really so bad, that we need to come up with a clever way to avoid writing brackets?
JRuby pros:
- Smaller library (800k)
- I kind of like the language more. One of the things I want out of a scripting language is closures, the whole passing-functions-as-data thing. Python certainly supports closures, but the difference is Ruby encourages them, by making them so easy to do. Looking at Ruby code, you see them all over the freaking place.
JRuby cons:
- Not really finished. It seems like most of the upcoming work is for tighter integration with Java, which I don't really need except as far as it increases performance. But there's some important stuff missing, like continuations. I've never ever used a continuation, but maybe I want to!
- Performance concerns. I know that the point of a scripting language isn't high performance, but when I look at this, it makes me worried.
But anyway, I think I'm going with JRuby, as that language seems more like what I want.
Seriously, you can seemlessly call back and forth between the two in both directions, and you can expose only the classes/methods from Java that you want.