[jules]

A bytecode specifically for Javascript would probably be sub optimal for performance of non-javascript languages. I'd rather have something lower level like .NET/Java bytecode or perhaps even LLVM.

[blasdel]

A bytecode for JS would be more optimal for other languages than the status quo: compiling to lexical javascript.

I they added a few extra bytecodes for stuff like TCO or goto or integers, it'd be pretty fantastic.