Mozilla has accepted Microsoft's recent offer for help in getting the Firefox browser and Thunderbird email client to run properly under Windows Vista. According to a reply posted this week to the Mozilla developers forum by Mozilla spokesman Chris Beltzner, "for the record, yes, we'd definitely be interested in some 1:1 support. The facility and program that you describe should really help to ensure that we get the proper integration issues looked at for Firefox 2 and Thunderbird 2." A week ago, the head of Microsoft's open-source lab invited Mozilla developers to Microsoft's Washington campus for a four-day work session with the company's Vista engineers. "We have, of course, been testing on Vista, and Rob Strong has done some work with Ed Averett to ensure that we take advantage of the new 'Default Program' infrastructure," Beltzner went on in his message. Default Program is a Vista feature that provides a single interface where users decide which software does what job, such as playing music files or browsing the Web. It's meant to replace the settings scattered inside applications, like the "default browser" option within Firefox and Microsoft's own Internet Explorer. Beltzner ticked off several areas where Mozilla could use some help, including how Vista's new application security mode will affect Firefox and Thunderbird, integrating with Vista's common RSS data storage, and tying in with the built-in Vista calendar and address book. He also offered Microsoft a piece of advice. "Something like a checklist of the most common OS integration points that have changed from Windows XP would be extremely useful, and would also be accessible to organizations that can't afford to send people to Redmond," Beltzner concluded. Microsoft and Mozilla compete in the browser space, and to a lesser degree, on the email front. Mozilla's Firefox 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 to under 80 percent from a high in the mid-to-upper 90s. Both Microsoft and Mozilla are working on the next generation of their browser. On Wednesday, IE 7 for Windows XP went into Release Candidate 1 (RC1), while Firefox 2.0 is slated to head into Beta 2 next week.