IT'S a great thing to behold a gathering of 10,000 people united by one cause. The result is a quasi-religious experience that must have accompanied the birth of social and political movements in the past.

The cause they believe in is Linux - a version of the UNIX computer operating systems that is underpinning a movement within the computer industry called "open-source software".

The event was LinuxWorld a gathering of the tribes of Linux at the San Jose convention centre in Silicon Valley last week.

The movement's prophet is Linus Torvalds, the soft-spoken Finn who invented the operating system while still a 21-year-old student eight years ago.

Perhaps it is sacrilege to compare Linux to the world's great ideological beliefs, but to the bearded, sandal-shod programmers attending the convention, Linux is more important than any political belief. It's what they do all day every day.

Open-source software is important to these developers for a number of reasons: it is free or very cheap to obtain. It is developed co-operatively by enthusiastic users instead of a giant corporation. The source-code is available allowing developers to tailor it to their needs, and it is not Microsoft.

"There is nothing like collective hatred to concentrate the mind," said one programmer at the show. "We hate Microsoft because they are trying to take our freedom of choice away. Linux gives us that choice again."

Indeed, there is a stark contrast between the long-haired leftist types attending LinuxWorld and short-haired chino-wearing Microsoft clones I witnessed attending the Microsoft TechEd Developers conference in New Orleans last year.

It is the difference between the Stepford Wives and Woodstock. Not that the computer industry's version of free love is immune to being violated. It is beginning already.

Some of the attendees viewed the presence of the large software corporations such as Oracle, IBM and Sun as the beginning of the end for Linux. Others viewed their presence as the coming of age of the operating system.

In the press room, computer companies like Intel, IBM and Corel were holding back-to-back press conferences in the hope of cashing in on Linux's popularity.

During one of the keynotes, some attendants complained of nausea as Oracle's slick marketing guru, Mark Jarvis, presented an info-mercial on the Oracle 8 database while making just a few cursory references to Linux.

Still, while the large software corporations' stands stood half-empty, programmers flocked to a small corridor at the back of the hall known as The Ghetto. There, the founder of the Free Software Foundation, Richard Stallman, awed fans with insightful witticisms and Rob Malda, the 22-year-old founder of www.Slashdot.com "news for nerds" website, sold T-shirts and baseball caps. It was the only money changing hands at the show.

Certainly, Mr Torvalds is the reluctant prophet and told attendees to calm down. "There's always a danger of overhyping Linux, and I just hope people will just be realistic," he said during his keynote speech. "We want to take over the world but we don't have to do it by tomorrow - it's OK to do it by next week, or even next month," he joked with the crowd.

Despite his reluctance to play software visionary, Linux has been enormously successful and its user base is growing faster than any other operating system.

"This is not about lofty ideals because I am a lazy person and I don't care about you," he said. "I just want to do something fun and useful."

Even a nun who works as a graphic designer in Los Angles, Sister Deborah Butcher, was wandering the floor. However, Sister Deborah is not yet a Linux convert. She had come to the show to have a look at what the operating system had to offer. But the message is clear. Linux is on the rise and conference attendees not only view it as their right to use the operating system, but see it as their mission to convince others that it is more stable, reliable and faster than any software that Mr Gates has to offer.

One such evangelist is the grey-bearded Jay Sulzberger, the proprietor of LXNY, an organisation dedicated to bringing Linux to public schools and libraries in New York City.

"I believe that there is no good reason for any public body such as a school or a library to pay for software when Linux offers them a faster better and cheaper alternative," he said.

Mr Sulzberger's organisation won a $12,000 (€11,084) grant to further his good work in sending out volunteer programmers to train local school staff and students.

"Guess what? Microsoft is about to get softer," he scoffed as he accepted the award.