Many VMs are designed to run from bytecode. This is true for Squirrelfish (Safari) and TraceMonkey (Mozilla), though V8 compiles directly to machine code. The bytecode isn't compatible, but it's not a stretch to imagine a JS bytecode language would be similar to these current IRs:
Anyways, I still believe that shipping an existing VM, be it .NET's CLR, Java's JVM or Python's bytecode isn't the right way to go. There's a lot of innovation left on the current web platform - both in terms of the performance work that browser vendors are pushing out and the new desktop APIs that the admittedly slow web standards committees are publishing. In the case of a platform as wide as the web, it makes sense that browser vendors sit back and built something from scratch.
http://webkit.org/specs/squirrelfish-bytecode.html
https://developer.mozilla.org/en/spidermonkey/internals/trac...
Anyways, I still believe that shipping an existing VM, be it .NET's CLR, Java's JVM or Python's bytecode isn't the right way to go. There's a lot of innovation left on the current web platform - both in terms of the performance work that browser vendors are pushing out and the new desktop APIs that the admittedly slow web standards committees are publishing. In the case of a platform as wide as the web, it makes sense that browser vendors sit back and built something from scratch.