Hey guys. This is a question for all the advanced Mac programmers here. I bought Synergy a while ago and it got me wondering how programs like this work. For those who don't know, Synergy controls iTunes from a little spot in the menu bar. Of course, on Windows you'd do this through COM, but how is it done in OSX? Does each applciation need to expose some sort of IPC interface by itself for this kind of control to happen? Or is there something built into the OS?