Microsoft opens up virtualization API

A key API of Microsoft's hypervisor technology will be open sourced.

Microsoft has announced that a key API of its hypervisor technology will be open sourced.

Microsoft's Open Specification Promise saw the company vowing to drop intellectual-property and patent claims, making them available licence-free for anyone to use.

Microsoft said: "With the OSP, any individual or organization is free to implement, commercialize and modify Microsoft's virtualization format technology for free, now and forever." The OSP initially involved 35 of its Web service protocols but now also includes its virtual hard disk image format, four security technologies, two XML file formats and a robotics protocol.

Now Redmond has added to the OSP the hypercall API that is central to Windows Server virtualization (code named Viridian) which will be available when Windows Server virtualization is released to manufacturing (RTM).

In the interim, Microsoft said that it has posted an updated draft of the hypercall API so that developers can gain early access to the interface. Microsoft first distributed hypercall API draft documentation to attendees of Windows Hardware Engineering Conference (WinHEC) 2006.

The hypercall API enables guest OSes to call for resources from the hypervisor. According to Microsoft, it enables development of software that builds on Viridian and is, said Microsoft, "available for use by any organization seeking to integrate or extend their software with Windows Server 2008 and Windows Server virtualization".

Microsoft continues to maintain that Viridian will RTM within 180 days of the RTM of Windows Server 2008, currently scheduled for Q1 2008.

Reactions

Two of Microsoft's close partners endorsed the OSP move. Both sell virtualization technology based on Xen, which was originally open source, and whose creator, XenSource, was bought by Citrix earlier this year.

"The majority of our customers have mixed-source environments, and they want their platform vendors to make things work together," said Roger Levy, Novell's senior VP and open source general manager. "That's why we entered into a technical collaboration agreement with Microsoft. As a result, Novell is the first vendor to develop and ship technology that will allow a para-virtualized Windows Server 2008 to be hosted as a guest on the Xen hypervisor.

"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 virtualization solutions that deliver true interoperability between Windows and Linux."

"Citrix is committed to the delivery of value-added virtualization solutions for the Windows platform, so interoperability with Microsoft's virtualization solutions is key to our success. This is made possible by Microsoft's open and progressive approach to licensing key technologies such as its VHD image format and the Windows Server Virtualization hypercall API," said Citrix CTO Simon Crosby. "This will allow us to ensure that virtual machines created on XenServer will be compatible with Microsoft WSV when it is delivered as a component of Windows Server 2008."

Microsoft applied the OSP to its virtual hard disk image format in October 2006, mirroring a similar initiative by market-leader VMware. VMware has also opened its virtual machine format, some of its management interfaces, and a number of its hypervisor APIs. VMware also pointed out that: "Microsoft's licensing policy has some restrictions on transferring licences from one server to another. Under Microsoft licensing, Windows Server licences are tied to physical hosts and do not move with virtual machine environments."

Join the PC World newsletter!

Error: Please check your email address.

Our Back to Business guide highlights the best products for you to boost your productivity at home, on the road, at the office, or in the classroom.

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Manek Dubash

Techworld.com
Show Comments

Essentials

Lexar® JumpDrive® S57 USB 3.0 flash drive

Learn more >

Microsoft L5V-00027 Sculpt Ergonomic Keyboard Desktop

Learn more >

Mobile

Lexar® JumpDrive® S45 USB 3.0 flash drive 

Learn more >

Exec

Lexar® JumpDrive® C20c USB Type-C flash drive 

Learn more >

HD Pan/Tilt Wi-Fi Camera with Night Vision NC450

Learn more >

Audio-Technica ATH-ANC70 Noise Cancelling Headphones

Learn more >

Lexar® Professional 1800x microSDHC™/microSDXC™ UHS-II cards 

Learn more >

Budget

Back To Business Guide

Click for more ›

Most Popular Reviews

Latest News Articles

Resources

PCW Evaluation Team

Michael Hargreaves

Windows 10 for Business / Dell XPS 13

I’d happily recommend this touchscreen laptop and Windows 10 as a great way to get serious work done at a desk or on the road.

Aysha Strobbe

Windows 10 / HP Spectre x360

Ultimately, I think the Windows 10 environment is excellent for me as it caters for so many different uses. The inclusion of the Xbox app is also great for when you need some downtime too!

Mark Escubio

Windows 10 / Lenovo Yoga 910

For me, the Xbox Play Anywhere is a great new feature as it allows you to play your current Xbox games with higher resolutions and better graphics without forking out extra cash for another copy. Although available titles are still scarce, but I’m sure it will grow in time.

Kathy Cassidy

STYLISTIC Q702

First impression on unpacking the Q702 test unit was the solid feel and clean, minimalist styling.

Anthony Grifoni

STYLISTIC Q572

For work use, Microsoft Word and Excel programs pre-installed on the device are adequate for preparing short documents.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?