The VMware vSphere vCenter Server Appliance (vCSA) is a niflty little management option available with all kits and editions of vSphere, letting you manage your environment with almost* all the bells and whistles without needing a separate Windows license.
Sounds great right? (and it is!) Want to try it? Go to the Evaluation site and sign up for a free trial.
Note that if you already have a vSphere deployment and just want to download the appliance you will need to go to the vCenter download page and specify 5.0.0 using the Version dropdown because (at the time of this writing) the vCSA is not available with the SP1 update
*vCSA doesn’t support IPv6 native, Linked Mode, vCenter heartbeat and using SQL as a database server. You’ll still need a Windows license for VUM.
If you have 3rd-party plugins you’ll want to check with them regarding vCSA support.