Microsoft and Turbolinux., a Tokyo-based Linux distributor, are cozying up with a patent cross-licensing deal and agreement to work more closely together, the companies said this week.

For users, one of the most significant elements to the deal is a pledge to work on a single sign-on system that will allow log-on to Windows-based and Turbolinux-based machines with one set of credentials.

At present Windows and Turbolinux machines on a mixed network can't access a common authentication database, but their deal should change this, said Noriko Otake, a spokeswoman for Turbolinux in Tokyo.

To further this work and other cross-platform projects, the two companies have also entered into a patent cross-licensing deal, specific details of which were not disclosed.

Interoperability testing of single sign-on and other future projects will take place at Microsoft's offices in Beijing. Turbolinux is active worldwide but has its strongest footprint in Japan and China.

Turbolinux will also add Microsoft's Live Search service to its desktop operating system.

The deal expands cooperation between the two companies that is intended to remove some of the hassles of using Linux, said Otake. Earlier this year Turbolinux added Windows Media Player to its platform, allowing users access to the large amount of content online encoded in that format, and the company has also been working on support for the Open XML document format.

Turbolinux also said it will participate in the Interoperability Vendor Alliance, a Microsoft-sponsored community of software and hardware vendors.

For Microsoft the deal is the latest in a string of over 200 patent-licensing agreements signed since it launched an intellectual property licensing program in late 2003. Last week the company announced a similar deal with Japanese digital imaging vendor Olympus, and previous agreements have included Novell, Fuji Xerox, Linspire, Kenwood, LG Electronics, Nortel Networks, and Samsung Electronics.