"You are never completely without doubt," when starting a venture such as Sun, Khosla. "Those of you who are thinking about [forming a startup], you've got to just jump in and do it," he said.

Sun's early systems replaced DEC machines that also ran Joy's Berkeley Unix software, Bechtolsheim said. "What [customers] were going to get with the Sun machine was exactly the same software at one-tenth the price of the hardware," said Bechtolsheim.

Pondering how much opportunity there is in the computing industry today, Joy said there has been an increase. "There's more opportunity now than before because there's more disciplines in which there is the same kind of opportunity," Joy said.

But Joy does expect the industry to have difficulties in continuing to boost performance in hardware. "We're getting down to places where metals don't scale," Joy said. Technologists could migrate to a different technology, he added. Khosla was more optimistic, saying he did not believe in limits.

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