Today I perused the source code of eucalyptus 1.4 and I was a bit surprised to find out that it's written in C, even when most of the system interaction is done through libvirt. I have to say this makes me a bit queasy. Python/Ruby/(insert your favorite high-level language) would have excelled at that game.

Eucalyptus is an open-source implementation (not production-ready) of a compute cloud API-compatible with EC2. In academia sysadmin time is very expensive so the roll-out has to be really simple. Eucalyptus currently uses xen and includes a security layer that replaces Amazon's use of the credit card authentication/authorization system. Mention of ROCKS, a cluster deployment system.