Microsoft has announced the arrival of Ray Ozzie, who has been appointed to be the company’s new chief software architect in place of Bill Gates.

Ozzie, 50, created IBM’s Lotus Notes and is widely regarded as a pioneer in how computers can be used for collaborative work. Microsoft's plan is for him to work "side by side" until 2008 with company founder and Chairman Bill Gates, also 50, who turned over the chief software architect's job to his colleague and good friend.

In July 2008, Gates will leave behind the day-to-day work of Microsoft to focus his attention on philanthropic work through the Bill and Melinda Gates Foundation, which he runs with his wife.

The foundation has assumed an important global role in health care, including work to eradicate diseases such as malaria and polio, as well as contributing millions of dollars to helping people with AIDS. While the decision to make this career change was "hard," Gates said in a written statement that he believes "the road ahead for Microsoft is as bright as ever."

Ozzie's presence surely must contribute to Gates's optimism. When Groove Networks, the company he founded in October 1997, was acquired by Microsoft in April 2005, Ozzie was named chief technical officer to great fanfare.

Before founding Groove, Ozzie was founder and president of Iris Associates, where he created and oversaw the early development of Lotus Notes.

He had played a key role in developing Lotus Symphony, as well as Software Arts' TKSolver and VisiCalc, and his official Microsoft biography further notes that he also worked on early distributed operating systems at Data General Corp.

He has a bachelor's degree from the University of Illinois at Urbana-Champaign, which has honoured him as a distinguished alumnus. It was at the U. of I. that Ozzie is said to have first become intrigued with collaborative systems and how computers can support collaborative work.