This would almost be funny, except that it's not forks, it's chopsticks...and you can eat perfectly well with ONE FUCKING FORK.

Thanks Jim :)

The Jython team has done only preliminary work on performance, and stands to gain a lot more over the coming months. They've recently undergone a rewrite of much of their code and are now stabilizing back toward a 2.5-compatible release. Performance work will probably come after that. And if they apply the same techniques we're using in JRuby, they'll probably do well.

If you have benchmarks showing V8/TM/SFE perform within an order of magnitude of C on something general-purpose (not a bloody fib benchmark) I'd love to see them as well. I have not seen such numbers in my searching.

I agree that V8/TM/SFE are great JavaScript implementations, but they're largely *just* that, JavaScript implementations. JS is a vastly simpler language than either Python or Ruby, and the performance characteristics will reflect that. In short, JS simply does less "magic" for you behind the scenes. That magic is frequently what makes Ruby and Python harder to optimize, but it's also what makes them more attractive as general purpose languages. So it's a matter of what you can get done with what code; if JS is 10x faster than Python but you have to write 10x as much code to get the same things done, where does that put you?

There's a fundamental difference here: those of us targeting existing VMs have a lot less work to do to go as fast as the C/C++ impls...and then faster. In JRuby, the basic, dumb implementation of Ruby performs around as well as the C impl. In some cases it's faster, and in some cases it's slower. But when we actually start implementing it *well* we get substantially improved performance. And even better, we can make improvements in days that take the C/C++ impls months or years to do, simply by continuing to structure JRuby in such a way that the amazing JVMs out there can optimize it well.

V8 and Tracemonkey do a lot to optimize JavaScript, but there's an important detail missing in almost all benchmarks of them: they make JavaScript less slow, but do not in any way bring it to the performance level of Java.

JVMs like Hotspot are the best hope for fast dynamic languages in the near future.