Q. What is xensource?

[augmento]

A. check their site http://www.xensource.com/Pages/default.aspx

[dwatson]

I think that is an old link. http://www.xensource.com/ works though.

[Viperman]

It is another virtualization product.  The company was bought by Citrix about 1.5 years ago.  They do a bare metal install very similar to VMware's ESX product.  They don't have quite the functionality or ease of setup that VMware has with their ESX product.