I\'m trying to find an API to control iTunes on OS X. I found the following:
http://developer.apple.com/sdk/itunescomsdk.html
I imagine on OS X, what I need
If you are looking for the API spec for the OSX applescript interface then run the AppleScript Editor (comes with OSX) and select File->Open Dictionary and choose iTunes from the list.
AFAIK, There is only an SDK (via COM) for Windows.
In Mac OS, iTunes is controlled via AppleScript.
There are quite a few tutorials running around, but I'm not familiar with anything official. In fact, last time I looked, they gave links to third-parties.
e.g., Tutorial
There is also Karelia's iMedia Browser. Source available under a BSD-style license.
If you are using Cocoa then I would recommend the (non-apple) framework EyeTunes.
Applescript may be your best bet though, either through calling a script directly or the ScriptingBridge framework available for Ruby, Python, and Objective C.
For the documentation, look at iTunes script dictionary (drag the iTunes icon onto the Script Editor icon).