opencoin and ripple
We, opencoin, are a project that started in 2007 to create an open source version of the electronic cash system invented by David Chaum. It is about minting tokens that can be transfered in a non-tracable way. It is fast, and the user has full flexibility on how to do the transfer.
We have nothing to do with "OpenCoin Inc.", a new company that is developing the ripple network. Unfortunately they decided in 2012 to name their company the same as our project. That creates a bit of confusion, as both are about electronic transfers.
So, if you want open source digital cash, opencoin.org (or our repo on github) is the place to be. If you want an account based system like the ripple network, it is not.