Fire and ice, or "Ballmer and . . .

The fire to Gates's ice, Ballmer emerged long ago from Gates' shadow -- and more recently became a YouTube star thanks to stunts such as jumping out of an oversized birthday cake on Microsoft's 25th anniversary, dancing and shrieking frenetically at a Microsoft employee meeting to earn himself the nickname "Monkeyboy" and almost rupturing his vocal cords while shouting "Developers!" 14 times at another Microsoft meeting.

Former Sun Microsystems CEO Scott McNealy derisively called the Microsoft brain trust "Ballmer and Butt-Head." Ray Noorda, the late Novell CEO, had a perhaps even less flattering nickname: "The Pearly Gates and the Em-ballmer: one sets you up for heaven, and the other prepares you for death."

But critics say that the only embalming work Ballmer has done lately is on Microsoft itself. The company's revenue growth and profit margins may remain the envy of the industry, but its stock price is up just 7 per cent over the last 5 years. Apple's stock, by comparison, has risen 1,500 per cent in the same period, while Google's is up nearly 500 per cent since that company's 2004 IPO. Even IBM, the ultimate blue chip, has seen its stock price rise 47 per cent since 2003.

Thus far, Microsoft has failed to duplicate the success of its certified hits -- Windows, Office and its server software (think Exchange and SQL Server) and development tools (Visual Studio) -- on any of the many bets it has made in recent years: search, Web advertising, mobile phones, video games and others.

Moreover, even with ongoing technical facelifts, Microsoft's stars are starting to show their age. Office is under heavy siege from online competitors led by Google Docs, while Windows Vista has become a PR debacle for Microsoft, in part because of the company's passive response to Apple's "PC and Mac" ads.

"Vista is not that bad, but Apple's disparaging has made it so Microsoft doesn't own its own image anymore," Enderle said.

At 6'1" and 225 pounds, and owning a voice louder than a high school gym teacher, Ballmer is known for his fearsome tirades, such as the time in 2004 when he allegedly threw a chair across a room and launched into an expletive-filled rant about Google CEO Eric Schmidt after being told by a key Microsoft developer that he was leaving to join Google.

Nonetheless, Ballmer may lack Gates' competitive ruthlessness. According to an anecdote in Bad Boy Ballmer , a computer industry CEO once told Gates and Ballmer, "You shouldn't kill the competition, you should leave the companies wounded. . . . Corpses look bad and attract attention." Gates "couldn't understand that," Maxwell wrote in the book. "He wanted 100 per cent of any market he could get. Ballmer was quiet."

And in its recent story, The Wall Street Journal quoted Microsoft executives saying that Ballmer, by working to settle many of the lawsuits filed against the company, has taken a more conciliatory approach toward legal opponents than Gates usually did.

Management-wise, Ballmer is also turning out to be a bit of a Micro-softie, in Enderle's eyes. Many of the executives reporting to Ballmer are "just not doing well," Enderle said. He added that while Ballmer continues to exhort his team to do better, a CEO like Hewlett-Packard's Mark Hurd "would've already changed the players."