Jeff Sandquist, Microsoft senior director of evangelism (left) talks about Channel 9 on the set of “This Week in Channel 9” as hosts Brian Keller (center) and Dan Fernandez (right) look on. (Dan Schlatter, Puget Sound Business Journal photo.)

The room could almost pass for a professional TV studio -- with an “On Air” light outside the door and two engaging hosts sitting in front of the cameras, offering a rundown of the week’s news against a cheery backdrop.

But it’s actually inside a Microsoft building in Redmond. The hosts are Microsoft employees. And the backdrop turns out to be a strategically lit shower curtain.

It’s all part of Channel 9, a video site launched by the company’s technical evangelists in April 2004 as a window into the offices -- and minds -- of Microsoft’s engineers and executives. Now approaching its fifth anniversary, the site has given Microsoft a way to communicate directly with the outside software developers who use its technologies.

Some bloggers and reporters remain wary of Microsoft sidestepping them to build an audience for its own internal media property. But communications experts call it a model for other companies seeking ways to engage their partners and customers.

“More and more companies are trending this way,” said Chris Kraft, president of Dallas-based strategic communications company Splash Media, which has worked with companies including Microsoft competitor Adobe Systems Inc. on their own online video initiatives.

Microsoft reports 4.5 million unique viewers a month for Channel 9. And in the ultimate sign of acceptance, Bill Gates made sure to sit down for a Channel 9 interview before announcing his plans to step down from daily life at the company.

Along the way, Channel 9 has spawned a small media empire. Its sister sites include Channel 10, for tech enthusiasts; Channel 8, for students; and VisitMix.com, which features content and working sample code for Web developers.

However, some longtime “Niners,” as the site’s regular users are known, worry that Channel 9 has become less genuine as it has supplemented its trademark raw interviews with more elaborate online productions.

“They really tried to get slick,” said Paul Mooney, a software developer in Morristown, N.J., who has been using the site since its launch, participating regularly in its “Coffeehouse” online forum. “The teams got bigger and they had to justify their existence. It’s sorta lost something.”

Mooney lamented the departure of some of Channel 9’s founding team, including well-known blogger Robert Scoble, who conducted many of the site’s original interviews.

But other observers continue to see value in what Channel 9 is offering.

Microsoft “did something useful, which is that they changed the way that they communicated with a very important constituency and in the process improved their reputation,” said Fred Vogelstein, a Wired magazine contributing editor who wrote an extensive piece on Channel 9 in 2007. “I actually think it’s even more relevant now.”

Vogelstein and Channel 9 gained notoriety when, in the course, of reporting on the site as an example of corporate transparency, he was inadvertently -- and ironically -- emailed a copy of the notes that Microsoft’s public-relations people had been compiling about his interviews. Although the notes said some unflattering things on topics including his longwinded interviewing style, Vogelstein said last week that he harbors no ill will over the situation.

In recent years, Channel 9 has added highly produced pieces, such as a series it recently launched on Microsoft’s history.

But the site also continues to offer new videos in the “classic” Channel 9 style – raw interviews in the offices of Microsoft employees and engineers.

Jeff Sandquist, the Microsoft senior director of evangelism who oversees Channel 9 and related sites, points to examples including a recent interview in which Microsoft technical fellow Mark Russinovich offered details on the upcoming Windows 7 operating system. It has received more than 527,000 views.

Perhaps the best-known Channel 9 interview was conducted in the early days of the site. Bill Hill, a Microsoft researcher, asserts in that video that Windows isn’t the most important operating system.

“It’s Homo Sapiens Version 1.0,” Hill says, making the point that software developers need to design their programs for people, not computers. “It shipped about a hundred thousand years ago, there’s no upgrade in sight, but it’s the one that runs everything.”

Over the past year, one useful addition is “This Week on Channel 9,” in which Microsoft evangelists Dan Fernandez and Brian Keller round up the highlights from the voluminous blog posts and other materials produced by Microsoft employees and product groups each week. That show is recorded in the ad-hoc studio inside a Microsoft building.

[See related video: Behind the Scenes at Channel 9.]

However, Microsoft hasn’t been as successful trying to replicate Channel 9’s success on some of its sister sites.

Channel 10, launched in 2006 at www.on10.net, gets about 1.4 million unique viewers a month. But it hasn’t developed the quality of online community that Channel 9 has. Channels 10 posts often go without comments, for example.

Part of the reason is the increasingly distributed nature of online communities, Sandquist said. Discussions about content often take place nowadays on Twitter, FriendFeed and other social networks. Sandquist and his team spend part of their days watching and participating in conversations about their content on those sites.

Vogelstein, the Wired contributing editor, pointed out that developers are Microsoft’s core audience, often staking their careers on the company’s direction. That’s no doubt one reason why they’re so engaged with Channel 9, whereas tech and Windows enthusiasts and have many options beyond Channel 10.

Sandquist, who was part of Channel 9’s founding team, cited planned changes in user interface that will create more natural connections between the various communities on the different sites.

All of the sites follow a fundamental concept, he said: “We have an audience, sometimes they’re technical, but all walks of life, and we want to give them access to our employees in a way that they can understand where we’re headed.”

Channel 9 co-founder Lenn Pryor, who has since left the company, named the site after the United Airlines in-flight channel that lets nervous passengers reassure themselves by listening in on the cockpit.

That metaphor continues to apply, Sandquist said.

“If that plane all of a sudden takes off and goes to the right and you don’t know what the heck’s going on, you’re going, what the hell?” Sandquist said. “Our customers are the same way. If a schedule gets slipped and we don’t tell them, they’ve bet their whole livelihood on us."