I'm guessing you mean apps that allow me to be productive. Not considering Twitter and IM clients, here's my list: * Terminal.app * The Python interpreter (I

I'm guessing you mean apps that allow me to be productive. Not considering Twitter and IM clients, here's my list: * Terminal.app * The Python interpreter (I use Python for things like automating tasks, renaming and reorganizing files and even as a simple calculator) * TextMate * A nice little todo app called Anxiety (http://anxietyapp.com http://anxietyapp.com) * iCal * A web browser. I prefer Opera, but I really don't care as long as it's not IE6. * xPad (sweet and simple note taking program) And, of course, XCode and Interface Builder for writing Cocoa apps. There's only one app from Linux that I miss on OS X: AmaroK (or something equally powerful). I know I can get AmaroK on OS X, but there are way too many dependencies. I'm also not willing to sacrifice 400MB of disk space for a media player.