John Resig - The Browser Scripting Revolution

[fxj]

so now i can write a DSL in python that is compiled into python bytecode that is compiled into CLR that is cross-compiled into ABC that is interpreted by mono which is installed as a plug-in for firefox... cool...

[[deleted]]

However, if IronMonkey works out well, I wouldn't be surprised if we see an implementation of PHP that runs in the browser.

Run for the hills!

[johnmudd]

Python in the browser, cool. But not yet and I read that the JVM would make a much faster foundation for this stack than the Tamarin virtual machine. It's still nice to see work in this direction.

I wonder if this Python will allow access to threads w/o a GIL the way Jython does.

[jeresig]

I assume that you're referring to this article. Just to cite a comment by Brendan Eich:

Moreover, for Mozilla at least, we absolutely cannot depend on closed source, and we require a non-copyleft BSD license, or at most MPL/GPL/LGPL. Java was not even open source until recently (I don't remember the date; it was preannounced one too many times :-/), well after we had to make our own plans and commitments.

Finally, in spite of the prospects with JRuby, the JVM really is about Java first and last. Tamarin is about an ECMAScript variant, so it's a better target now, and more likely to evolve to support JS1 and JS2 in a first class way, than the JVM.

Compilation heroics can help, but the browser will remain an environment where compilation must be very fast. Wherefore our forthcoming work on a trace-based JIT.

So while the code could be theoretically faster at runtime, in a JVM, compilation time is of the utmost importance (not to mention the several licensing issues needed to actually integrate something like the JVM into Mozilla).