Gambas - Gambas Almost Means Basic. Ok, and now it gets really wild, but I thought after RealBasic I can't help but also link to Gambas, a kind of VisualBasic clone for various systems. Can work with different databases and different GUI libraries. And a port to OSX is now available (June 2011, so still quite fresh), which also sounds promising for the future, as Linux and Windows are already supported. And yes, I know, "real" programmers turn up their noses at things like VisualBasic, but it is very useful for quickly putting together graphical tools and is particularly interesting for occasional programmers.
