As people have commented, I'm suggesting writing a javascript function which takes pre-compiled bytecode; like so;

    function interpret(bytecode) {
        // stack machine implementation goes here
    }

And called like so;

   var bytecode = load("http://my.domain.com/myscript.bytecode");
   interpret(bytecode);
     

I'm not suggesting that bytecode is inherently slow -- just that I could take a great stab at writing a slow bytecode interpreter in JavaScript. ;)

So under this scheme, you could do a server-side compilation of any language -- let's imagine Pascal as an example -- and deliver it back to the client as bytecode. Now you've broken the browser dependence on Javascript. At the cost of a VM written in JavaScript.