The SCO Group's website was accessible again on Monday after being down for about three days, the victim of a denial of service (DOS) attack launched by a "senior" member of the open source community, according to open source advocate Eric Raymond.

SCO released few details of the attack except to say that its sco.com site had been unavailable to Internet users starting on Friday because of a denial of service attack and was back in operation at around noon PST (Pacific Standard Time) Monday.

The attack was perpetrated by a member of the open source community who was upset with SCO's escalating conflict with the Linux community, according to Raymond, who said that he had been in contact with an associate of the attacker.

Though Raymond said he did not know the attacker's exact identity, he offered a few details. "He's one of us. He is part of the community around open source software and the Internet infrastructure and he's pretty senior," Raymond said.

DOS attacks come in a variety of forms, but they generally are designed to disable a Web site by overwhelming it with useless network traffic.

Last weekend's attack was not the first assault on sco.com. In early May, the Web site was shut down for several hours, again due to a DOS attack.

SCO is working with the U.S. Federal Bureau of Investigation to pursue charges against the author of the May attack, and company executives have complained in the past of being unfairly victimized by overzealous Linux fans.

The Lindon, Utah, company has raised the ire of the Linux community by claiming that the Linux kernel contains code that was illegally contributed in a variety of fashions, and by threatening to sue Linux users over these alleged violations. Earlier this year, it sued IBM for over US$3 billion, saying that Big Blue had inappropriately added code that was derived from SCO's Unix System V software. SCO has also maintained that Unix code has been directly and illegally copied into Linux, though the company has yet to provide any compelling evidence to substantiate its charges.

In an interview last week, SCO Chief Executive Officer Darl McBride complained of being picketed, targeted with crank telephone calls at 2 a.m., and even challenged to a fist fight by a SCO detractor.

"Terrorists do things designed to intimidate people, and we see a lot of that going on all the time -- people trying to attack us or people that we're associated with," he said at the time. "If you look at a DOS attack, that's a form of cyber-terrorism," he said. "when you're shutting people's Web sites down, you are impacting commerce. That's against the law."

Raymond and fellow open source advocate Bruce Perens condemned the attack, saying that the open source community would be better off compiling evidence against SCO's claims, rather than attacking SCO directly. "I think it's important that we hold the moral high ground here," said Perens. "We are the good guys. We are the ones who are having false claims made about us."