"Like many IT executives, I took great offense to Ballmer's comments," Strasnick wrote in an e-mail. CitiStreet uses Red Hat Linux widely in its data centers. "If Microsoft really thinks there is some code in Linux that violates their patents, they should publish those lines of codes immediately instead of just posturing in the press. [Fear, uncertainty and doubt] may have worked for IBM in the 1970s (some of us are old enough to have been around then), but not today."

When Linux began gaining adoption by dot-coms in the late 1990s, many mainstream CIOs considered it risky in part because of their unfamiliarity with the open-source General Public License (GPL) that governs the operating system's intellectual property, according to Gordon Haff, an analyst with Nashua, N.H.-based Illuminata Inc.

"It wasn't that any circa-1999 CIO had carefully studied the IP issues surrounding Linux, it was that they didn't know much about them and the whole thing sounded kind of fishy to them," he said.

Those risks appeared to become realized in 2003, when The SCO Group, a former Linux distributor-turned licenser, began suing both Linux vendors IBM and Red Hat Inc. and ex-customers, such as AutoZone and Daimler-Chrysler, for infringing upon its copyrights.

But SCO has made little progress in its lawsuits. Meanwhile, many open-source vendors, including Hewlett-Packard Co., Red Hat, SUSE and others, quickly responded by offering indemnification against potential lawsuits as part of their standard support packages to customers. Others, such as IBM, have long maintained indemnification was unnecessary.