In addition to the store systems, the company has 45 servers running Novell's SUSE Linux operating system and Oracle Corp. 's 10g database in its central data center. Prince said he chose Linux for its stability, ease of remote administration and similarity to Unix. "There's never been a virus in a store computer," he said. "I never have to worry about things like that."

But Gordon Haff, an analyst at Illuminata Inc. in Nashua, N.H., said Windows' lingering reputation for insecurity and instability is without merit. He also noted that many retailers look at the availability of POS applications and equipment, where Windows still has an advantage over Linux, more than they consider the merits of the operating system itself. "The operating system is a small piece," Haff said.

Ritz Camera Centers Inc. in Beltsville, Md., is a case in point -- but on the Linux side of the ledger. In August, the 1,200-store chain announced plans to upgrade its 4,000 Unix POS terminals to SUSE Linux. Bob O'Hern, Ritz Camera's senior vice president of information systems, said this month that the retailer is moving to Linux partly because it wanted to run a Java application called Xstore from Datavantage Corp. in Cleveland.