As others have mentioned (thanks guys!), our Untirends Free only protects VMware, Hyper-V, & Windows clients, however our paid editions start at $299, which is a one time cost, and includes the 1st year of support. After the initial year, the only costs that you'll have going forward will be for support, which includes tech support & all software updates. This post about our updated XenServer protection went up on our blog yesterday. Please let me know what questions you may have.