This is a tutorial on the basics of a program called Quartz Composer that can be used for things like iMovie backgrounds, effects, transitions etc.
Download instructions:
Go to https://developer.apple.com/devcenter/mac/index.action . Register for a new account (top right) and then click on "Xcode 3.2.6 and iOS SDK 4.3". Quartz Composer *should* come with XCode- if it doesn't leave a comment.
