There are quite a few of these p2p content-addressed storage systems out there: OFFSystem, Dat, Freenet, IPFS, I2P, Maidsafe, ... Does anybody keep an overview

There are quite a few of these p2p content-addressed storage systems out there: OFFSystem, Dat, Freenet, IPFS, I2P, Maidsafe, ... Does anybody keep an overview? Has any of them achieved serious use yet?