Microsoft's long, strange trip with Windows Vista came closer to an end Friday as the company released the first release candidate of its next-generation operating system. Windows client vice president Jim Allchin, who plans to retire after Vista's release, made the announcement in an e-mail to TechNet subscribers.

"It's official -- RC1 is done," Allchin said. "We could not have achieved this milestone without your support. The quantity and quality of feedback and data we received from you has been essential to helping us progress."

"Quality will continue to improve," he said, adding Microsoft had made some adjustments to the user interface, added device drivers, and made some performance tweaks. "We'll keep plugging away on application compatibility, as well as fit and finish, until RTM."

As usual, the build will first be released to a small number of selected testers through its TechBeta community. MSDN and TechNet subscribers will gain access to the bits next week, followed by a broader release to the public, meaning as many as six million testers could have their hands on the build in the coming weeks.

Mary Jo Foley, noted Microsoft pundit and author of Microsoft Watch, explained that the company's very short period between Pre-RC1 and the RC1 build had a lot to do with Microsoft's internal goals.

"Microsoft is trying to stick to an internally set, roughly once-monthly Vista drop schedule. Many testers expected them to do their regular August drop 2-3 weeks ago," she said, referring to the company's plans announced last year to issue monthly builds of the operating system, a plan it hasn't always been able to hold.

Foley also used the same explanation to make sense of what was widely seen as a disaster for the company: Vista's bug-filled and crash-prone Beta 2 build. "They were just trying to stick to the updated internal release schedule," she said.

According to leaked information from both Microsoft Canada, and pre-order information on Amazon.com, Microsoft apparently has a January 30, 2007 release date for Vista. While the company will not confirm, industry insiders said the planned release timeline makes sense considering there would likely be at least two release candidate builds before Vista's release to manufacturing in November.

However, analysts have said Microsoft is cutting it extremely close in making its release date goals. "The signs are favorable, but nothing is certain," JupiterResearch senior analyst Joe Wilcox said.

"Right now, it's too close to call and say for certain whether Microsoft will have a bright sunny Windows Vista release or the stormy skies of delay," he continued. "I don't see how anyone can make an accurate forecast until Microsoft starts getting feedback from Windows Vista Release Candidate 1 testers."