I am running:
Zimbra 5.0.7 Open Source Edition on openSUSE 10.2
Zimbra 5.0.7 Open Source Edition on openSUSE 10.3 inside VirtualBox
Zimbra 5.0.7 Open Source Edition on Ubuntu Server 8.04 LTS inside VirtualBox 1.6.2
Currently testing 5.0.8 on openSUSE 11