Crunchy-like sites for javascript and ruby

While I have been aware of the Try Ruby site for quite a while, recently I came across this interactive javascript tutorial. While none of these are nearly as flexible as Crunchy, they are nice resources that are currently available for anyone to try without needing to install anything. It would be nice if I could have a dedicated server running Crunchy in a sandbox so that people could try it out without having to download it.