Microsoft's Post-Gates Management Team

Though Bill Gates leaves his full-time duties at Microsoft on Friday, he remains nonexecutive chairman and will participate in select projects at the direction of Microsoft's current executive management team. Below is a rundown of who they are and what some of their near-term challenges are in Microsoft's post-Gates world.

-- Steve Ballmer, chief executive officer and the man in charge of it all. Ballmer's main challenge at the moment is to figure out a way for Microsoft to put a dent in Google's advertising dominance now that the Yahoo deal has fizzled. Ballmer also must help Microsoft diversify its revenue base, which still mainly comes from Windows and Office. He also must lead Microsoft through Gates' transition and prove to everyone that he can carry Microsoft forward even without Gates by his side.

-- Ray Ozzie, chief software architect and the new "Bill Gates." Ozzie is responsible for transforming Microsoft from a packaged-software vendor to a formidable Web 2.0 player in its own right. He is in charge of architecting the company's Web-based services strategy and attacking Google head-on. Ozzie obviously has the brains and visionary mettle to create technology that is forward-thinking and can change the way people live and work, but does he have the eye of the tiger when it comes to competing as a business man? Another question surrounding Ozzie's position as Gates' heir apparent is whether CEO Ballmer will let him have as much free rein to execute on his vision as longtime pal Gates did.

-- Craig Mundie, chief research and strategy officer. Mundie is to Microsoft's long-term innovation and research what Ozzie is to the short-term strategy of capitalizing on the Web. Entrusted with helping Microsoft compete overseas, particularly in emerging markets, Mundie faces pressure from Linux and open source in regions where Microsoft's products are too expensive to buy. He also is pressured to inspire Microsoft's brain pool to continue to innovate and come up with new ideas for future groundbreaking technologies.

-- Kevin Turner, chief operating officer. Turner is responsible for global execution and field alignment worldwide. In an interview, he said he slowed down Microsoft's transition to hosted services because he wanted to make sure customers were ready for it. Now he must prove that was a good idea. Turner is also challenged to help guide customers and Microsoft's own sales teams through the transition as Microsoft undergoes the fundamental business-model changes required to pull it off.

In addition to Microsoft's top companywide executives, the presidents of each of Microsoft's three divisions also are key players in architecting Microsoft for life after Gates.

The chief challenge for Robbie Bach, president of the Entertainment and Devices Division, is to make Microsoft's Xbox business, which has been enormously expensive for the company, pay off in revenue. There's no doubt Xbox has been a successful product in the consumer market, but it has to start reaping in cash for Microsoft as the company tries to diversify its revenue beyond its core businesses.

Kevin Johnson, president of the Platforms and Services Division, must continue to defend Microsoft against fallout from the disappointment Windows Vista has been among customers, and help the company transition its OS to a world where the Web is becoming more important than the PC. Johnson also has Microsoft's weak Online Services business under his care and is pressured to turn that segment around for the company in its quest to compete with Google.

Finally, a new player, Stephen Elop, who joined Microsoft in January as president of its Microsoft Business Division, will have to pick up where longtime Microsoftie and predecessor Jeff Raikes left off. Like Gates, Raikes is flying the coup for The Bill and Melinda Gates Foundation: He will take over as CEO of the philanthropic foundation when he leaves Microsoft in September. Elop has under his charge the successful Office business, but is challenged to live up to Raikes' impressive legacy and continue to move Office beyond mere productivity into collaboration. The Business Division also oversees Microsoft's business applications, which remain locked in a constant battle for market share with powerful rivals Oracle and SAP.