By Tim Weber
Business editor, BBC News website
The announcement that Microsoft founder Bill Gates is slowly withdrawing from the daily running of the company did not come as a surprise.
The writing had been on the wall since January 2000, when Mr Gates handed over the reins as chief executive to his friend from university days, Steve Ballmer.
During the past few years Mr Gates had already spent more and more time on the charitable foundation he had set up with his wife Melinda.
Some critics - and he has many - have described Mr Gates as a cold and calculating brainiac. But when he speaks about the good causes supported by his foundation, there is a rare passion in his voice.
Mending the ills of the world is indeed close to his heart.
Aids, Malaria, TB - the silent mass-murderers of the 20th and 21st centuries - are among the diseases that he hopes cutting-edge technology can beat.
Mr Gates, famous and notorious for his attention to technical detail, involves himself closely in many of the decisions about how the Bill and Melinda Gates Foundation spends its massive $29.1bn endowment.
It is this passion that Mr Gates now hopes to dedicate his life to. He calls it a "re-ordering of my priorities."
Continuity for Microsoft
The only surprise of Mr Gates's announcement was the timing.
Like many large companies, Microsoft often finds it difficult to keep a secret. Announcing the change now has pre-empted any rumours that might have emerged.
Team Microsoft: Gates, Mundie, Ozzie and Ballmer
Microsoft has also outlined a two-year transition period, which will calm investors and customers.
Steve Ballmer is already in place, experienced in motivating and cajoling the company's workforce - and customers.
Ray Ozzie, a much-respected veteran of the software industry who joined Microsoft just last year, will take over Mr Gates's crucial role as chief software architect.
Working for the next two years alongside the company founder, he will be able to promise continuity to Microsoft's most important customers - the many IT buyers in the corporate sector, most of whom remain suspicious of rival operating systems such as Linux or Apple's Mac OS or productivity software such as Open Office.
Craig Mundie, the man behind many of Microsoft's mobile computing solutions, will take on Mr Gates's role in leading the company's research and strategy efforts.
Microsoft's share price said it all: it barely moved after the announcement was made.
The Bill Gates legacy
As one of the founders of Microsoft, Bill Gates helped lay the foundations of today's digital world.
The next two years should give Mr Gates just about enough time to cement his technological legacy.
2007 will see the launch of the consumer version of Microsoft's much delayed Vista operating system.
It will look flashier than the company's current offering Windows XP, and it may look and feel slightly cuter than Apple's current OS X.
Bill Gates has defined our digital world
The key changes, though, will be under the bonnet. If Microsoft's techno evangelists can be believed, Vista's architecture will make Windows computing much more reliable and secure.
Meanwhile the Xbox 360, Microsoft's next-generation games console, is intended to help the company move out of the office and into the living room.
And finally Microsoft is now pushing into the market for software-on-demand, under the brand Windows Live.
This move, offering all kinds of software online and in a browser, will not only help the company take on its new nemesis, Google.
More importantly, these on-demand tools are intended to make Mr Gates's digital vision a reality.
It is a world where software is "user-centric" and your digital world accompanies you wherever you go - in the office, at home and on the road.
It is the holy grail of digital "convergence".
The stumbling blocks
In two years' time, when Mr Gates hopes to pass on the reins, this converged world could also be a world where Microsoft is everywhere.
Of course, there are plenty of challenges to overcome. Linux is slowly breaking out of its software developer corner. Google continues to be at least two leaps ahead in the on-demand stakes.
And Apple has spoilt Mr Gates's master plan with its success in the world of music and video players.
Mr Gates, though, argues that his company has always had to face new competitors and challenges.
"There isn't any time in our history when there haven't been questions about Microsoft," he said.
During the next two years, Bill Gates hopes to answer most of them.