The companies announced that their respective hypervisor products (the small piece of code that decouples software from hardware devices, and the lynchpin of virtualisation) would be interoperable.

Users will be able to move virtual machines between Citrix’s XenServer environment and Microsoft’s Windows Server 2008 with Hyper V when the latter is released later this year.

Today's announcement goes some way to deflect suspicion that the companies' cordial relationship could not continue as they move further into competition in the virtualisation space. But that only serves to heighten speculation surrounding their partnership.

Citrix’s remote application delivery products rely on Microsoft’s Terminal Services product to work in Windows environments. Citrix therefore acts as a Microsoft reseller, selling Terminal Services licenses to its customers.

In turn, Microsoft allows Citrix engineers to sit in its labs and see how its products work - and therefore design application delivery products that suits Microsoft's software.

The cordial relationship between the two companies has, to date, been mutually beneficial. In virtualisation, however, they compete. Both have hypervisor products and desktop, server and application virtualisation solutions built on them.

In light of today’s announcement, that competition seems insufficient to sour the relationship for the meantime. Speculation that Microsoft will buy its old ally – thereby both easing this potential threat to their relationship and catching up with virtualisation leader VMware –  is now approaching deafening volumes.

Calista acquisition

Microsoft also announced a move to improve the user experience of its virtualisation platform.

The company has agreed to acquire, for an undisclosed sum, Calista Technologies, a Californian software developer that improves the graphical quality of virtualised Windows desktop environments.

This will allow companies which regularly use 3D graphical visualisations or video to virtualise their desktop environments – a technique that to date has been denied them by deteriorating image quality. It should also make standard virtual desktop deployments more reliable. 

Further reading

Citrix finds a competitive streak Citrix aims to virtualise Windows before Microsoft can

Citrix leans on Windows Still endebted to the fat client king.

The new virtual platform The virtualisation revolution has just begun. Expect the most radical benefits to appear at the processor level. Find more stories in the Systems Management Briefing Room