Gearpunk and Steampunk for your True20 games. It is in interesting book. Not set in any particular genre or time the illustrations are evocative of Victorian Steampunk, Pulp and even weird science. The rules are fairly straight-forward on how to build various machines; almost as if they were characters in their own right. Feats and skills are discussed. If you have True20 or a TRue20-based game and want to add some gear based machines (no Matric here yet) to it then this a great little book.