The ATL wiki is the root of all the documentations. The first four pages below are converted into an Eclipse documentation plugin embedded into ATL SDK builds. You can contribute them using a bugzilla account.
ATL Use Cases:
This section provides a set of ATL model transformation use cases covering different domains of application. These use cases are concrete examples of how model to model transformation (MMT) can be applied.
Families to Persons (PDF version, Powerpoint version):
This presentation describes a very simple model transformation example, some kind of ATL "hello world".