Bitgem (BTG) is the 4th PPC fork (after NVC, BTB, YAC). Although it doesn't have much innovation the dev appears to be actively maintaining it. An active fork of PPC is an acknowledgement of our work and let more developers get familiar with PPC's design and code.
Bitgem is not currently traded on an exchange. So I added it to PPC Marketplace (
http://ppcoin.org/market) to help its users to trade.
Good luck BTG!