First: CEPH is the closest I've seen. And it is pretty damned good. Two reasons: 1. Colossus is extremely dependent on other Google Tech to work and be cool.

First: CEPH is the closest I've seen. And it is pretty damned good. Two reasons: 1. Colossus is extremely dependent on other Google Tech to work and be cool. Implementing 'just colossus' without the rest of the tech stack would require developing quite a diverse set of other tools first. 2. Part of what makes it cool is that everybody is mandated to use it, and hardware, kernel and so forth improvements are made to make it better.