Microsoft has made the programming interface for its Viridian virtualisation technology available to third-party software developers.
Its decision should improve compatibility between virtualisation products running on the forthcoming Windows 2008 server operating system.
On his Microsoft blog, Jeff Woolsey from Microsoft's virtualisation team, said, "Microsoft will extend the Open Specification Promise to the hypercall application programmer's interface [API] within Windows Server virtualisation [codename Viridian]."
An updated draft of the hypercall (API) is now available on Microsoft's website.
This interface provides the specification for the virtualisation technology being built into Windows Server 2008. These APIs are available for use by any organisation seeking to integrate or extend their software with Windows Server 2008 and Windows Server virtualisation, Woolsey said.
Novell has said it will ship virtualisation products using the Microsoft API. What this means is that Windows Server 2008 will be able to run as a guest operating system on the Xen hypervisor virtualisation software, which ships with its SuSE Enterprise Server 10 Linux product. "Microsoft's decision to put the hypercall API under their Open Specifications Promise will make it even easier for Novell, our customers and partners, and the entire open source community to develop high-quality virtualisation that deliver true interoperability between Windows and Linux," Roger Levy, senior vice-president and general manager.
Simon Crosby, chief technology officer of the Virtualisation and Management Division of Citrix, said access to Microsoft's technology will ensure that virtual machines created on Citrix's XenServer product will be compatible with the virtualisation component of Windows Server 2008.
Windows Server virtualisation is scheduled to be available within 180 days of Windows Server shipping, which is expected February next year.