I was just wondering what Tools/IDE's OS X developers here like to use for Rapid Application Development (apart from X Code)? I've had a play with RealBasic, which seem pretty cool, and of course there are loads of Java IDE's. Are there any others? I'm especially interested in those that compile to native machine code that don't require runtimes (like Mono or Java). Cross platform development would be good too, that's plus for RealBasic I guess.