Cloud Foundry - Make it Yours!. Interesting project for building a cloud platform based on Ruby. The source is freely available on Github. CloudFoundry is probably what runs under ActiveState Stackato (where Perl and Python are supported). Such a private cloud can also be quite interesting for your own projects, because you can develop locally at home or on the go, and the deployment to your own root server is simple and easy. At some point, I think I want to set something like this up (currently, every service is set up individually for me, which can be quite annoying in the long run).