Oh, Mono running natively on Mac OS X, thanks to Gtk+ Native widgets. But “MonoDevelop has pretty much the same feature parity than Linux does. There are a few missing features that we hope to resolve in the future, and there is plenty of room to improve.” Because multi-platform languages aren’t.
Edit 1: And no, this is not a post to prize Mono. All credit goes to the Gtk+ guys who managed to do the hard work of porting Gtk+ to use the native widgets. Actually, I’m pretty disgusted that De Icaza is again trying to sell Mono taking credit of other people’s work.