(FORTUNE Magazine) – BILL GATES SAYS HE HAS TRIED TO recruit software star Ray Ozzie "for a long, long, long time." But the man who created Lotus Notes liked his independence and didn't want to join the empire. Finally, in mid-March, Gates got his man--by buying his whole company, Groove Networks, the 200-person software company Ozzie started in 1997.

Getting Ozzie is like the Yankees signing several All-Stars. He is, by acclamation, one of the world's top programmers, and he is coming into Microsoft at an astonishingly high level, as one of three chief technology officers. Gates says he wants his new hire to influence the entire span of Microsoft's software.

Ozzie is unusual among technologists for his intuition. He has an empathic understanding of how people need to communicate when they work. That's a big reason Notes, the first major software for collaboration, became one of the most successful applications in history. (Ozzie still has a 1984 letter from Gates saying he wished the project--then just starting--could have been done at Microsoft.) Says an unusually effusive Gates: "Ray's really pretty phenomenal, not just as a great engineer but for how he thinks about what workers want to get done. As what we call the 'digital workstyle' moves to be much more about collaboration, there's no one who has thought about that more."

Groove's software enables people to work jointly on documents or conduct conversations in text, voice, or video in secure "spaces" online. Users connect over the Internet in a peer-to-peer fashion, directly accessing data off one another's computers. Groove does this so securely that it's popular at the Pentagon. Microsoft plans to add Groove to the Office suite and to put some of the code into the next version of Windows.

Ozzie is an independent thinker who doesn't, for example, dismiss the importance of open-source software, something Microsoft views as a scourge. He's also a fan of Skype, free Internet phone software that's turning telecom upside down. He certainly has a more open-minded sensibility than one generally associates with Microsoft.

So why, after years of resistance, did Ozzie decide to join the colossus now? As a small company with a hard-to-understand product, Groove just wasn't getting enough traction. Sitting in his sunlight-filled office in a converted shoe-machinery factory in Beverly, Mass., Ozzie talked about Groove not as a business but as a mission (an attitude that hasn't always endeared him to investors): "I have very significant goals for large-scale impact with this style of collaboration." By joining Microsoft, Ozzie gets access to the software giant's clout and capital; Microsoft gets Ozzie's brain. It looks like a good deal for both sides. -- David Kirkpatrick