July 19, 2006, 2:08 PM — VMware has slammed Microsoft's tie-up with open source virtualization developer XenSource, announced earlier this week, calling it a "one-way street," and accusing XenSource of betraying its open source roots.
The agreement between the two companies will allow a para-virtualized Windows to inter-operate with XenSource's Xen, and significantly add to Xen's appeal by making Windows Server virtualization able to run open-source Xen-based guest operating systems.
VMware has criticized the deal however saying that while it will optimize Microsoft code to run on the Xen hypervisor it does not allow Microsoft-XenSource developed code to be used by the open source community.
Brian Byun, the company's VP of products and alliances, pointed out in his blog that the deal is "a one-way street that favors Microsoft and Windows running Linux.
The arrangement will allow Linux to run on future Microsoft hypervisors through translated calls to the hypervisor when Windows is controlling the hardware, but not the other way around.
That means there is no mention of Longhorn optimizations or 'enlightenments' being ported to Xen or licensed to XenSource to enable a Xen hypervisor to run full optimizations with Longhorn OS."
Byun accused XenSource of abandoning its open source roots, with the result that its code would become proprietary.
He said that XenSource was enabling Microsoft to build proprietary layers and APIs, adding: "It stands to reason that in order to protect Windows from GPL contamination, XenSource will need to undertake a lot of non-GPL development to translate and buffer the Linux kernel from Windows hypervisor interfaces.
"And nothing that Microsoft licenses to, or develops with, XenSource is GPL and can be used directly by the Xen or Linux communities and commercial distributions."
Byun commented too on the timing, saying that: "It
