On: JavaScript in JavaScript (js.js): smaller, faster,...

[bri3d]

Even more evil would be to use JRuby and TheRubyRhino: run a JavaScript JavaScript implementation in a Java JavaScript implementation bridged to a Java Ruby implementation! To boot, the Rhino approach is probably a lot slower, since TheRubyRacer uses libv8.

[DHowett → bri3d]

You could probably get a hilarious optimization out of it[0] by using gcj to compile the set of classes that JRuby generates into a native binary.

Or, you know, use dx and transcompile it to Dalvik bytecode.

[0]: Unfortunately, JRuby gives gcj/gij a hard time - gcj hits an internal error and gij makes it report that gij is unsupported. :(