ConVirt is a centralized management solution that lets you provision, monitor and manage the complete lifecycle of your Xen deployment. This is wonderful for Open Source Xen! I am looking forward to giving this a shot during my Xen deployments.

More info here

The project is sponsored by Convirture.  From their website:

Convirture was founded in 2006 to solve an acute problem faced by an increasing number of businesses. As open source hypervisor packages gained functionality, more and more data centers and QA and test labs had begun to deploy them, both to increase the range of applications running on virtualized infrastructure, and to lower the overall cost of virtualization. As companies began to use open source virtualization platforms to solve their strategic business challenges, they ran head-first into a new challenge: the overhead and complexity of managing open source virtualization platforms