Mercurial Repository
Just like libHSPlasma, Age Creator is stored in a Mercurial repository. The URL to clone from is http://dev.zrax.net/hg/AgeCreator/.
Bug Reports & Feature Requests
The issue tracker is here. Bug reports and feature requests are encouraged, but remember that development is still early, and most of the obvious stuff (support for more Plasma objects, being able to move objects around, and a bunch of others) are already planned, so please don't go overboard on feature requests yet