He could have been as rich as Bill Gates, but Ken Sakamura says he's fine earning enough to lead an "ordinary life."

In the world of computers, the obscure Japanese engineer stands in the top rank along with Gates, having developed an operating system that is more widely used than even Microsoft Corp's Windows.

Sakamura's system, TRON, is used to run items ranging from digital cameras to car engines, just as Windows operates personal computers.

What sets the two systems apart -- and the fortunes of Sakamura and Gates -- is that while Windows must be bought from Microsoft, TRON is distributed free of charge.

Had Sakamura decided to charge even one cent to each user of TRON, he would easily be a dollar billionaire by now, possibly even rivalling Gates, reputed to be the world's richest man with a fortune estimated at $43 billion by Forbes magazine...