Citrix Systems and Microsoft inked a five-year, code-sharing deal that will make sure customers of Citrix's MetaFrame Access Suite have a migration path to Longhorn.

MetaFrame Access Suite, running on Microsoft Windows Terminal Server, lets multiple devices access applications on a server. The agreement maintains Citrix's access to Windows Server code and will ensure a solid migration path for Citrix customers when Microsoft moves to the next version of Windows Server, which will be part of the product group code-named Longhorn.

"The premise of our business is to mitigate change and understand the evolving, heterogeneous world," said David Jones, senior vice president of product development for Citrix. "[Otherwise], as new platforms came, there would be 'access spaghetti.'" Users would have to log in and out of different applications using multiple passwords. Instead, MetaFrame Access Suite handles switching between applications and devices behind the scenes.

"Customers don't jump to the new platform immediately," said Nabeel Youakim, Citrix area vice president for Microsoft global relationships. Instead, he said, customers use a mix of Windows technologies, relying on MetaFrame to provide a single access point. Therefore, Youakim said, "Our first step is to make sure MetaFrame runs on Longhorn."

The Longhorn Windows Server System is expected to ship in 2007, and Citrix will continue to build out MetaFrame to take advantage of the capabilities in Longhorn. Youakim said that Microsoft has given Citrix a general idea of what it plans for Longhorn Server, but no real details.

The deal includes a new technology collaboration agreement and patent cross-licensing between the two companies, extending a relationship that began in 1997 when Citrix licensed Windows Server 3.51 source code. Citrix later licensed to Microsoft for $185 million the thin-client technology it had developed. That technology became the base for Microsoft's Terminal Server.