It's definitely possible to start with MacRuby. It just requires a little more overhead to translate Cocoa documentation into methods that work with MacRuby (no

It's definitely possible to start with MacRuby. It just requires a little more overhead to translate Cocoa documentation into methods that work with MacRuby (not to mention the occasional one that doesn't work right...). As a Rubyist, there's definitely some differences (named parameters, for instance), but you get the hang of it pretty quick. As a Cocoa developer, debugging with MacRuby has issues, as Xcode doesn't always know about the right symbols since it's not compiled (but this is getting better!). Use the MacRuby book, and learn to love Xcode's documentation, and you should be good to go. If you do have issues, email the macruby-devel mailing list or visit #macruby - the community is super friendly and happy to help! re iOS: I'm really hoping. With MacRuby shipping by default with Lion, iOS 5 will hopefully follow suit this summer.