Bill Gates, the man who founded and built Microsoft into the world's dominant software company, announced Thursday that he would end his day-to-day duties with the company by 2008 to devote more time to his charitable work.

Gates, 50, said he wants to focus on global health and education work at the Bill and Melinda Gates Foundation.

Microsoft chairman and chief software architect Bill Gates smiles during a news conference in this Feb. 13, 2001, photo.
(Elaine Thompson/ Associated Press)

The company announced a two-year transition "to ensure that there is a smooth and orderly transfer of Gates' daily responsibilities." It said Gates would continue to serve as the company's chairman and an adviser on "key development projects" after he steps down at the end of the transition period in July 2008.   

"This was a hard decision for me," Gates said. "I'm very lucky to have two passions that I feel are so important and so challenging. As I prepare for this change, I firmly believe the road ahead for Microsoft is as bright as ever."

Gates gave up CEO job in 2000

Gates hasn't been Microsoft's CEO since 2000, when he relinquished the role to Steve Ballmer.

In the ensuing six years, Gates has served as the company's chief software architect, but will give up that job immediately.

Gates founded Microsoft with childhood friend Paul Allen back in 1975, building it into a software empire that is now worth $225 billion US. An estimated 90 per cent of personal computers built worldwide are shipped with Microsoft's Windows operating system.

Along the way, Gates also faced many legal challenges from governments and rival companies who accused Microsoft of not competing fairly.

Gates is worth $50 billion US, making him the richest person in the world — a title he's held for many years. He's donated billions to charity and his foundation is worth $29 billion US.