If it’s not enough for you to code scripting languages such as Groovy and JRuby and have them compile to bytecode and run on a JVM, howabout coding in Java and have it compile to Javascript with AJAX functionality to run in your Browser?
This is what Google have announced this week at JavaOne with their Google Web Toolkit. Sounds pretty impressive. I don’t know of anyone who enjoys working with Javascript, so this sounds like an interesting concept.