Proxmox Virtual Environment is a powerful Open Source Server Virtualization Platform, based on KVM and OpenVZ

Released 04.03.2013:

update qemu-kvm to 1.4.0
new kvm backup implementation, see Backup and Restore
added RBD (ceph) support on GUI
update kernel to vzkernel-2.6.32-042stab072.10.src.rpm
include latest Broadcom bnx2/bnx2x drivers
include latest Adaptec aacraid driver 1.2-1[29900]
update e1000e to 2.2.14
update igb to 4.1.2
update ixgbe to 3.12.6
enable CONFIG_RT_GROUP_SCHED (also update corosync if you install this kernel)
extend memory GUI to support ballooning
implement auto-ballooning
add HD resize feature to expand disks
updated network drivers (bnx2/bnx2x/e1000e/igb/ixgbe)
added omping binaries (for testing multicast between nodes)
update to latest Debian version 6.0.7
qcow2 as default storage format, cache=none (previously raw)
KVM64 as default CPU type (previously qemu64)
e1000 as default NIC (previously rtl8139)
task history per VM
Node Summary: added "KSM sharing" and "CPU Socket count"
enable/disable tablet for VM on GUI without stop/start of VM (you can use vmmouse instead, for lower CPU usage, works on modern Linux and on all Windows VMs as long as you install the vmmouse drivers)
bug fixes (for all details see bugtracker and GIT