More than 1,500 corporate customers had signed up for its Oracle's Unbreakable Linux support programme, attempting to prise users away from Red Hat's own support team.

Nearly all those customers had signed up during the past six months, with "virtually no selling at all," said Oracle CEO Larry Ellison during the company's OpenWorld user conference. "We did all of this while just building up our Linux sales team," he said.

At a price ranging from about $99 to $2,000 per year, the Unbreakable Linux programme provides support for Red Hat Enterprise Linux and Oracle's close clone of that operating system, as well as the applications that run on them.

Red Hat's Linux business continues to far outpace Oracle's - Red Hat CEO Matthew Szulik said in June that the company added "multiple thousands of customers" in its first quarter of fiscal 2008 alone. Nonetheless, user reaction at the show indicated that Red Hat may be vulnerable.

For example, Brad Maue, CIO at Stuart Maue, said the Oracle support offering is "half [the price] of Red Hat. And we feel we get twice the attention." The St. Louis-based legal auditing firm switched its Linux support from Red Hat to Oracle about a year ago, he said.

Tim Heath, a senior data­base engineer at Yahoo, said that his company turned to Oracle's Linux support offering after some bad experiences with Red Hat. "There were some bugs in Linux" that Yahoo couldn't get Red Hat to fix, Heath said.

Yahoo, which runs Red Hat Linux on 50,000 of its 150,000 servers, now has Linux support contracts with both Oracle and Red Hat, Heath noted. "We like to pit the two against each other to see who submits fixes faster," he said.

Yahoo has found that using Oracle's Linux support eliminates the "finger­pointing" between the applications and platform departments when a problem arises, he said.

Red Hat officials downplayed Oracle's Linux efforts. "This is not about offering better support," said Red Hat chief technology officer Brian Stevens. "This is about ownership of the IT stack for Mr. Ellison."