Several news sites reports today that Citrix is going to make XenServer available free, which is based upon the open source Xen hypervisor. Last year VMware released their own hypervisor, ESXi, for free.
Apparantly the big money isn’t in the hypervisor anymore, but the technology to manage them. Giving away your product is the best way to get more customers.
Citrix says their hypervisor, XenServer, has a couple of features not available throught VMwares ESXi, at least not without opening your wallet. For instance, ESXi is a 32-bit bare-metal hypervisor, whereas XenServer is a 64-bit bear-metal hypervisor. XenServer can also handle up to 8 virtual CPUs, while ESXi only handles 4.
Citrix has released a list of features included at no costs on their site.