Guessing what eye-popping growth figures Microsoft will trumpet for its popular portal and collaboration app, SharePoint, has become an annual parlor game for fans and detractors alike.

At Microsoft's first global conference for SharePoint in May 2006, which 1300 people attended in Seattle, Microsoft said the software had 75 million licensed users.

That number grew a year later to 85 million licensed users, and generating $800 million in revenue per year.

Last year, Microsoft reported more than $1 billion in SharePoint sales along with more than 100 million users.

At its sold-out worldwide SharePoint conference this week, expected to draw 7,000 to Las Vegas, Microsoft said that SharePoint is defying the company's slump, growing more than 20% to $1.3 billion, according to corporate vice-president for SharePoint Jeff Teper.

Teper hinted that SharePoint's licensed user base may be as high as 130 million today, saying its year-on-year growth was "roughly in relation to our revenue."

Windows' replacement?

That would seems to provide compelling evidence that SharePoint is preparing to enter Microsoft's pantheon of ubiquitous platforms along with Windows and Office. CEO Steve Ballmer has called SharePoint Microsoft's "next big operating system."

It's even more impressive, considering the software's short history. First introduced in 2000 under the name "Office Server Extensions" as a tool for hosting Microsoft Office documents on the Web, the software underwent several minor name changes, reflective of Microsoft's changes in positioning against incumbent collaboration and groupware apps such as Novell's GroupWise and IBM's then-dominant Lotus Notes.

Early on, SharePoint had the reputation of being a jack-of-all-trades that, out of the box, was a master of none, said Michael Sampson, a consultant and former analyst at Ferris Research.

"In 2001, I wrote a report that said, 'Don't touch it.' In 2004, I wrote the same thing. It wasn't until 2007 that I said, 'It's good enough,'" said Sampson.

Despite the zig-zagging, SharePoint grew quickly. A year and a half after the release of SharePoint Portal Services, the software had 7 million users.

Two years later, the software, now called Windows SharePoint Services, had more than quadrupled to 30 million users in January 2005.

Eighteen months later, that number more than doubled again to 75 million users, by which time the software had a new name, Microsoft Office SharePoint Server (MOSS), with WSS kept only for the free version.