It is open source, available at http://www.ubercomp.com/jslm32/src/

I did both an interpreter and a (much faster) dynamic code generator that generates blocks of code in Javascript so it doesn't have to decode every instruction over and over again.

Oh, and before doing the project, I sent Bellard an email, and he was very polite and helpful. Even sent me some compliments after I was able to optimize it to run at a decent speed. A true master!!!

EDIT: Looks like there is no iface though. I guess that shouldn't be a surprise. I didn't catch that until I tried to wget bash and see how long it would take to compile.