The high priests of free software have congregated at Google Inc. headquarters this week to debate the future of the movement and face down recent patent threats by Microsoft Corp.

Leading names of Linux, the world's biggest grassroots software phenomenon, are spending three days to Friday debating whether an increasingly commercial open source community should fight or ignore the world's largest software maker.

Dressed in the alternative software movement's casual uniform of T-shirts and jeans, the group is coming to grips with internal divisions that sap at its success -- Linux is now used to power desktop computers, major Web sites, mobile phones -- since rival factions often create very similar products.

But as many of the world's top tech companies and corporate customers demand ever more from Linux, open source devotees still fight among themselves with the fervor of a tiny monastic order seeking to root out theological error in their midst.

Guys: Be seekers of truth, not finders of contradiction, Jim Zemlin, executive director of the Linux Foundation, organizer of the event, only half-jokingly told the 150 attendees of what is billed their Collaboration Summit.

Linux is the best-known variant of so-called open source software -- software that is freely available to the public to be used, revised and shared. Linux suppliers earn money selling improvements and technical services. By contrast, Microsoft charges for software and opposes freely sharing its code.

Recently, Microsoft has sown dissension by claiming open source programs such as Linux violate 235 of its patents while striking deals to insulate the customers of two Linux suppliers -- Novell and Xandros -- from patent lawsuits.

On Thursday, Linspire Inc., which sells Linux-based personal computers through Wal-Mart and other retailers, became the third company to strike a patent deal with Microsoft.

MICROSOFT: ENEMY OR PUNCHING BAG?

Collectively, the group is militantly opposed to Microsoft, which some attending the summit openly refer to as the enemy.

But most believe Linux users control their own destinies and Microsoft's patent threats are just the latest attempts to create fear, uncertainty and doubt among customers. After closed-down sessions Thursday and Friday, the group aims to issue a consensus statement next week on what they plan to do.

James Bottomley, who works as chief technology officer at Steeleye Technologies, is in charge of maintaining the software code used by Linux to transfer data between computers and peripheral devices like printers, a job he does for pleasure.

Bottomley says Microsoft is unlikely to sue Linux customers because most Linux users also buy Microsoft. Their customers are our customers, he said, adding that: It's just bloody annoying. It gets everyone riled up.

Zend Technologies, developers of an open source programming language called PHP that is used in many Web sites, is seeking to remain neutral. Eighty percent of its customers use open source software, but it recently struck a deal with Microsoft.

I think Microsoft is a big company trying to make up its mind, said Zend Chief Executive Harold Goldberg, who is not taking part in the event.

On the one hand Microsoft has a big established business it is trying to defend, Goldberg said. On the other hand, there are those inside the company, though they won't admit it publicly, who see open source as the future.

WORKING TO WORK TOGETHER

This is the first conference of the Linux Foundation, an umbrella advocacy group formed early in 2007 to unite two predecessors, Open Source Development Labs and the Free Standards Group.

There are as many as 360 rival flavors of Linux, known as distributions, according to Distrowatch.com. This factionalism fuels rapid innovation but splits the energies of developers.

There really is a sense in many projects that there is an 'us' and a 'them', said Mark Shuttlesworth, founder of Ubuntu, a free, desktop version of Linux that competes with Windows. There are the folks who are inside a project and those who are outside a project.

The Linux Foundation boasts 70 corporate and non-profit backers, including Intel, Oracle, IBM, Cisco, Motorola, Nokia, NTT, Dell, Red Hat and Sun, along with major customers like ADP, Bank of America and Morgan Stanley.

Linux used to be worked on by professionals doing the work on their own time, said Jason Wacha, an expert on licensing Linux and attorney for MontaVista, a maker of Linux software for mobile and consumer electronics devices.

Ultimately, I think (Linux) is being pushed by commercial forces ... Now a lot of people are being paid to do Linux as professionals, he said of how many top open-source developers now work for big-name companies like Google, HP and Oracle.

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