OpenNode is a open source server virtualization solution providing easy to use bare-metal ISO installer. It's based on CentOS and supports both OpenVZ container-based virtualization and emerging KVM full virtualization technology on the same host.
Karesansui is an open-source virtualization management application made in Japan. It's smart graphical user interface lowers your management cost, and brings a total management/audit solution for both physical and virtual servers. Full featured RESTful interface allows customizing and integration with other management/billing systems.