I'm a very happy Google Closure Compiler user, especially with the "advanced optimizations" flag. It does a level of code elimination and variable renaming at a

I'm a very happy Google Closure Compiler user, especially with the "advanced optimizations" flag. It does a level of code elimination and variable renaming at a level that no other JavaScript tool even approaches. Excellent software. I think it gets a bad rap because you need to write your code in a certain way to avoid the optimizations breaking things. But if you're a disciplined developer, you'll reap some large benefits.