Does anyone know of any decent reference sites for writing an Xcode plugin at all? I've searched Google and only found one very short article of Apples dev site. I thought it might be quite fun to write a Mercurial plugin for Xcode 3 but finding any documentation is a bit of a pain. I also assume it requires some knowledge of using Applescript Studio which seems to be a little different to writing just a simple Applescript, am I right in that assumption? I've never touched Applescript before.