Microsoft has enticed Turbolinux into one of those "we-won't-sue-your-users" IP license like Novell, Linspire and Xandros before it.

The assurances, based on Microsoft's claims that Linux and open source software violate 253 Microsoft patents, are limited to users of the Turbolinux Server.

Sold largely in Japan and China, Turbolinux is the first Asian Linux distributor to sign on the dotted line.

Samba Project Jeremy Allison thinks from the sound of it that Turbolinux has signed away its right to distribute the next release of Samba, which will go out under the new GPLv3 license that forbids patent deals.

"We would have to see what the patent arrangements are" with Turbo, Linspire and Xandros, "but we will enforce the license," the soft-spoken Allison said with some vehemence. And without Samba Turbolinux won't be able to tap into Active Directory - unless Microsoft writes Linux code.

Besides the Free Software Foundation's own GNU components of Linux, Samba was first to adopt the new license, which grandfathers Novell's arrangement with Microsoft. Its GPLv3 code is still months off.

Anyway, in return for Turbo signing up there are promises of advances in the interoperability of Linux and Windows Server and further R&D collaboration beyond what the companies have been doing, including an interoperability lab at Microsoft's Beijing offices for customers and partners.

Microsoft and Turbolinux are particularly interested in developing a single sign-on covering both architectures.

Turbo has also signed one of Microsoft's royalty-free Workgroup Server Protocol Program (WSPP) evaluation licenses that Microsoft has just rewritten in light of its settlement with the European Commission this week.

Turbolinux is supposed to use it to weigh additional avenues of collaboration, Microsoft said. And Turbo will participate in Microsoft's Interoperability Vendor Alliance.

There's an earlier agreement between the two companies involving Turbo with the Open XML format and the use of the Windows Media Format. Under the new deal, Turbolinux desktops will include Live Search.

According to Turbolinux CEO Yano Koichi, "When strong Microsoft customers are evaluating Linux, we want them to see Turbolinux as the distribution that works best with their existing Microsoft investments."