Mind you Apple have done their level best to completely break applets anyway. Grr.http://shootout.alioth.debian.org/u32/benchmark.php?test=all&lang=v8&lang2=java
What, realistically, is the performance difference between Java 6 and the fastest JS engines out there at raw compute power and memory writes?
Regular expressions are super fast with V8. Generally Java (server) is at least 3 times faster. On average Java is about 5 times faster. And if you do something JS is pretty bad at, Java can be over 40 times faster.
I rarely have any problems. JSLint helps a lot.
"[...] classes, inheritance, mixins, traits, method modifiers and more."
Well, you can have classes and you can also have inheritance. Prototypal-inheritance, that is.
Something like, just embed a headless VM in Chrome (ie. without AWT and Swing). Pop in a decent API for DOM twiddling.[...]
Ah yea... DOM manipulation. This wouldn't be any faster with Java, C or C++. It's so slow because it's a super heavy operation. Reflowing (recalculating the layout) and redrawing are the slow parts. A faster language won't help there.
(Thankfully you don't have to touch the DOM for Canvas-based games.)