Until he launched his legal campaign last year, hardly anyone had heard of Darl McBride. Today, he's one of the most hated men in the computer software business.

"I believe his unpopularity far exceeds that of Bill Gates, who is No. 2," said software developer Ron Newman after hearing McBride speak at the Harvard Law School on Feb. 2.

"Bill Gates has produced something of value," Newman said of the co-founder of Microsoft Corp., who has been reviled for abusing his company's monopoly on desktop operating systems. But Newman said that McBride "has produced nothing of value."

Microsoft refused to comment on the popularity, or lack of it, of its CEO. But there's no question that McBride, chief executive of Lindon-based SCO Group Inc., is widely despised. He's a favorite target for bitter insults on leading Internet technology sites like Slashdot. He's gotten hateful e-mails and been peppered with nuisance calls after someone published his phone number on the Internet.

And the SCO Group Web site has been targeted by computer vandals four times in the past year. The computer worm Mydoom, which made worldwide headlines, caused infected machines to send billions of data requests to the SCO site, knocking it out of commission.

All because McBride has sued one of the world's largest computer firms — International Business Machines Corp. — and, in the process, threatened to derail the popularity of the free Linux operating system, a major rival to Microsoft Corp.'s Windows software.

According to McBride, IBM has taken software belonging to SCO and illegally contributed it to Linux. If the federal courts decide that he's right, McBride will have done what Microsoft can only dream about. He will have crippled the burgeoning growth of Linux — perhaps permanently.

Yet McBride sees himself as the sort of person the geeks of Slashdot should be rooting for — the head of a small business fighting for justice against a corporate giant. "We were forced into a corner where we had to fight," said McBride.

With 2003 revenues of $79.3 million, SCO Group is a relatively tiny software company, but it controls one of the most valuable properties in the industry — the powerful Unix operating system, one of the most popular operating systems for heavy-duty computing tasks. Most major versions of Unix, including an IBM product called AIX, are based on code invented at AT&T Corp. and now owned and licensed by SCO.