A few weeks back we introduced a type of non-binding agreement for Web services software called Open Specification Promise. Today we announced that the same agreement now aplies to the virtual hard disk (VHD) image format used by Microsoft for encapsulating the OS and app within a virtual machine. Some early coverage has appeared in eWeek and CNET. And Sam posted an audio interview with XenSource's Simon Crosby at Port25.

So what's this mean for the 60+ partners who previously licensed VHD under a royalty-free agreement? It means that you can either stick to the terms of the existing VHD agreement, or you can choose to accept the OSP terms. Your call.

And why should Windows Server customers care about this news? I'll venture to say that the friendlier terms of OSP will be appealing to more (than 60) vendors, who will then create new VHD-based solutions for Virtual Server and Windows Server virtualization. And I suspect many of these solutions will be interoperable with the open source world.

While the OSP news is goodness, the timing is a bit odd. Just yesterday our brethren on the Windows client team posted the new EULA for Windows Vista. There were some inaccurate interpretations of the EULA in regards to was is/isn't allowed when it comes to virtualization technologies. If you read the EULA - and you're not an attorney like me or many of us out there - it's not hard to misinterpret the language. An anonymous comment to Alessandro's post shared the correct interpretation:

This does not limit your use of the software in a virtual environment. It is intended to limit your use of the same license for multiple installations. For instance, if you buy a new desktop with a copy of windows installed, you can't take that same license of Windows and install it in a virtual machine. This would be similar to not allowing you to install the same license on another machine. Ultimate edition opens up licensing and allows you to use the same license inside a virtual machine, even though the license is already installed on the physical machine. 

I hope to see an official clarification from the Windows Vista team on this topic.

Patrick