How does Nimbus compare to OpenNebula?
OpenNebula is, like Nimbus, an open source framework that deploys and manages virtual machines on physical resources. The main difference is that while Nimbus exposes remote interfaces (based on EC2 or WSRF) and handles the related security issues, OpenNebula does not. Nimbus interfaces can be combined with OpenNebula virtual machine manager on the backend. In fact, such experimental integration has already been carried out, see here.
