Speaking at a European Technology Forum event in London on Thursday, McNealy claimed that his firm's open approach to computing--its Solaris operating system source code was made available in 1999 -- has given it a clear advantage over Microsoft, which has traditionally kept tight controls over its intellectual property.
"Our interfaces are open, so when there is a system problem we get help from the industry, but Microsoft flunked Sharing 101. I think that was a third year Harvard course," he said.
McNealy's jibe relates to the fact that Microsoft's billionaire chairman and chief software architect famously dropped out of Harvard to set up Microsoft with his childhood friend Paul Allen.
He joked that a lot of Microsoft's success could be put down to the fact that both Gates and Microsoft chief executive Steve Ballmer "got a head start" on their competitors by dropping out of university early. Ballmer spent a year at Stanford before joining the Redmond start-up.
"I was in Harvard when Bill quit early, I was in Stanford business school when Ballmer quit early. They had a head start on the rest of the industry," he said.
Despite a recent run of disappointing results and questions over the company's future -- as increasing numbers of potential customers opt to use Linux and Microsoft rather than Sun's Solaris server platform -- McNealy was typically bullish about the future.
"A lot of customers ask us, 'are you going to make it?' and I say 'how much cash have you got in the bank? Is that all? That's so sad.'"
The Sun chief executive -- whose children Maverick, Dakota, Colt and Scout are named after cars -- said that the IT industry is needlessly complex and should resemble the automotive or aerospace industries where customers simply buy a complete product rather than building it themselves.
He claimed that companies should be buying "gift-wrapped" software and server capacity from service providers rather than opting to build their own systems. "Most companies are going to stop buying components. If you want to fly you don't buy your own aeroplane. Do you know what operating system is in your car?" said McNealy.
Sun has traditionally aimed its high-end servers running on Solaris and its UltraSPARC III processors at the telecoms and Internet industries, but has recently seen this market shrink considerably.
Despite claiming that his company had done more than any other vendor to support Linux, McNealy, referring to the continuing lawsuit between SCO and IBM, warned that Linux users would have little protection if SCO was successful.
"IBM won't indemnify you for Red Hat software. This is a big issue," he said.
Andrew Donohue reported from London for ZDNet UK.