Introducing ivi - a Java Virtual Interface for VMware, Xen, KVM, and OpenVZ, ivi (pronounced eve-e) stands for Java Virtual Interface and it is a project that aims to create a single, graphical, management interface for all the major virtualization products. ivi is implemented in Java+Swing, so it is truly portable. Currently ivi uses the VI3 SDK to communicate with VI servers and the XenApi to talk to Xen servers. Future plans include adding support for libvirt to allow communication with KVM and OpenVZ, and eventually support for the Common Information Model (CIM) as a way to talk with VMware, Xen, and Microsoft all through one interface.
You can read more about ivi at http://www.lostcreations.com/code/wiki/ivi.