The lure of open source software is tempting - tales of enormous cost savings, freedom from vendor control and proprietary technologies, plus the broad resource of a community of volunteer programmers eager to help.

But every reward has its risks.

Ask Autozone; the regional auto parts dealer made the switch to Linux in all of its stores as a point-of-sale system in 2000, displacing SCO OpenServer. The SCO Group , which has brought a widely publicized lawsuit against IBM, claiming it infringed on Unix patents by promoting Linux, turned around and sued its own customer .

"IBM approached Autozone in an effort to induce Autozone to breach its agreement with SCO," the Unix vendor said in court papers. "IBM was actively advising Autozone's internal software group about converting to Linux . . . Despite the Autozone OpenServer License Agreement with SCO . . . IBM finally successfully induced Autozone to cease using the SCO software and to use Linux with IBM's version of Unix. Autozone ultimately decided not to pay SCO the annual fee to continue to maintain the SCO products and . . . with the encouragement of IBM, began the efforts required for conversion to Linux. . ."

In July, a Nevada court issued a stay, pending the outcome of the SCO vs. IBM case as well as SCO suits against Red Hat and Novell. Observers of the case say any penalties against Autozone are unlikely to ever come about because the IBM/Red Hat/Novell cases could be tied up for years. But until the case is resolved, Autozone remains mired in this legal morass (Read a related story on patent issues ).

Technical concerns

Some large enterprise users running Linux in the data center say that while the legal issues are real when using open source software, other risks, particularly around product support, are even more important to consider.

"There can be technical risks," in deploying open source software, says Joshua Levine, CTO and operations officer at E*Trade Financial in New York. His firm moved off of a Sun Solaris Web platform to Linux four years ago, and saved around $200,000 per server on hardware and software costs. Levin says there were great concerns as to whether a Linux switch would support the firm's trading applications.