The man formerly responsible for Microsoft's anti-open source strategy has warned that Linux is rapidly becoming a legitimate alternative to Windows.

David Stutz said while software written above the level of the single device will command high margins for a long time to come, the Redmond giant should stop looking over its shoulder and invent something better than open source.

Stutz, who retired from Microsoft this week, was a group programme manager for the company's Shared Source initiative.

This is a crucial effort by Microsoft to deal with the threat from the open source software movement, partly by sharing more code with universities and industry partners.

In a 'sanitised version' of his retirement message on his personal website (www.synthesist.net) Stutz said: "Recovering from current external perceptions of Microsoft as a paranoid, untrustworthy, greedy, petty and politically inept organisation will take years."

However, he added that "Microsoft is a wonderful place for those who want to jump in and express an opinion that is backed up by careful thinking".

Stutz's main attack was on Microsoft's PC-based strategy, which he argues is misguided in a computing world where complex networks are more important than single devices.

He maintained that the internet, the web and open source software projects, in which communities of programmers contribute improvements which are distributed free, are all part of the steady advance of networked computing.

Stutz suggested that Microsoft needs to focus on building a layer of software that integrates network technology.

But that layer should not be an operating system like Windows, which is tied to PC technology.

"To continue to lead the pack, Microsoft must innovate quickly," he said. "If the PC is all that the future holds, then growth prospects are bleak."

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