The message they offered the crowds echoed the longtime desire among Linux fans to see the open-source operating system loosen the stranglehold Windows enjoys on the desktop. But this time that message was leavened with criticism of the Quixotic strategies Linux proponents and vendors still often rely on.

One of the biggest obstacles to acceptance of desktop Linux by corporate IT is the perception that proponents of the OS are, well, troublemakers, according to Rob Enderle, principal analyst with San Jose, Calif.-based The Enderle Group. "The closest thing you have to a union in IT are Apple users and Linux users," he said. "Nobody else revolts like that."

CIOs, for ease of management, generally prefer that employees all use the same operating system. The rule of thumb Enderle subscribes to is that support costs increase by the square of the number of platforms. So if a company runs two operating systems, support costs increase by 4 times. If a company runs Windows, Mac and Linux, support costs increase 9 times.

But whenever CIOs openly try to consolidate operating systems, they run into pockets of resistance from diehards who say "nasty things and threaten to quit." Faced with that, most CIOs will simply try to limit the growth of Mac and Linux desktop systems "to maintain some respect and decorum, as well as keep their own jobs."

Nine million Linux PCs are expected to be shipped this year, according to IDC, growing to 17 million in 2008. While less than 4 percent of PCs expected to be sold in North and South America in 2008 will come with Linux, about 9 percent in the Asia-Pacific and Europe, Middle East and African regions will be.