Syntax Highlighting already exists for Java and XML, highlighting for Java Script (ECMA 232) would also be extreemly useful for us.

As most of our frontends are done in Flash, Action Script support would also be invaliuble to us if we were to use confluence as our documentation platform (which we do).

The only main difference between JS and AS is the list of predefined functions/classes/objects. The ability to have the JS predefined functions and then be able to add groups of predefined functions (eg: AS core functions, and then custom core api functions/classes/objects).