The head of Microsoft's open source software lab has extended a helping hand to Mozilla Corp. if it's interested in making sure the Firefox browser and Thunderbird e-mail client run under Windows Vista.

In a posting to the Mozilla development planning discussion group, Sam Ramji, the director of the lab, said he had set aside office space for open-source developers and would make Microsoft engineers available to Firefox and Thunderbird coders.

"As part of my mission as an advocate for open source applications on Windows, I've gotten spaces set aside at the Windows Vista Readiness ISV Lab," wrote Ramji.

"The lab itself is a 4-day event held in Redmond every week through December 2006; we provide secure office space for 4 people, hardware, VPN access, and 1:1 access to product team developers and support staff," he added.

Ramji also said that although Microsoft had invited only commercial developers to such labs in the past, "I'm committed to evolving our thinking beyond commercial companies to include open source projects."

Microsoft and Mozilla compete in the browser space, and to a lesser degree, on the e-mail front. Mozilla's Firefox, for instance, has grabbed about 15 percent of the global browser usage share since its debut in 2004; most of that was at the expense of Microsoft's Internet Explorer, which has seen its share fall from the high 90s to under 80 percent.

Both Microsoft and Mozilla are working on the next generation of their browser. IE 7 is currently in Beta 3, while Firefox 2.0 should head into Beta 2 form later this month.

No reply from Mozilla has been posted to the thread, and representatives from Mozilla were not immediately available for comment.