Proxmox Server Solution GmbH is building an open source management tool for virtualization platforms: Proxmox Virtual Environment.

The product, still in beta (0.9), has some interesting capabilities:

• Bare-metal installation (based on Debian Etch 64bit, which includes the supported virtualization platforms)
• Support for KVM and OpenVZ
• Web-based management console (AJAX based)
• Host-level backup (OpenVZ containers only)
• Support for host-level clustering (Proxmox VE Cluster)

Additionally, the developer is implementing also a live migration capability.

Since both KVM and OpenVZ don't have a GUI it's worth a try even if it's still in early development.

Download it here.