They claim the code shown was released under an open-source licence several years ago.
The ruckus erupted when SCO showed its "smoking gun" to delegates at its conference in Las Vegas yesterday. A German journalist photographed and published two of SCO's presentation slides. The slides then came under the full scrutiny of Linux advocates, with one, former Hewlett-Packard open source strategist Bruce Perens, publishing a damning analysis online.
Perens claims the code can be traced to AT&T, which developed the Unix code eventually sold to SCO, and was written as far back as 1973. Since then it has been released under varying licences as open source code -- Perens argues that even Caldera, the company now known as SCO, made the code open itself under a special license.
Furthermore, he said, it was released under the BSD license. Copies of the BSD code are freely available online and include the developer comments SCO allege were proof of code theft. "No violation of SCO's copyright or trade secrets is taking place," Perens argues.
Linus Torvalds, the creator of Linux, told ZDNet Australia by e-mail the alleged blunder wasn't a surprise. "Hey, that was what we claimed was the most likely source of common code from the very first time," he wrote.
"So one code snippet was from pretty much original Unix -- and yes, Caldera released the old Unix code itself back when they still remembered that they made all their IPO money off Linux -- which is interesting partly because it shows how SCO has been lying all along: they said several times how they are talking about SysVr4 code, not 'old Unix' code, and now they show old Unix code on their slides."
"The other snippet they showed was apparently from the 'netfilter' code, which is not old Unix, but is definitely BSD licensed and freely usable," he added.
While Perens says the SCO team did a good job of finding duplicated code, "they didn't take the additional step of checking whether or not the code had been released for others to copy legally".
"It strikes me that SCO would show their best example. This is it?!?!? Hoary old code from 1973 that's been all over the net for three decades and is released under a license that allows the Linux developers to use it with impunity? If this is their best example, they are bound to lose."
When AT&T took BSD to court back in 1992 in a case that is similar to the SCO lawsuit, AT&T, in the form of Unix System Laboratories, lost.
"Since Plaintiff has failed to provide enough evidence to establish a 'reasonable probability' that Net2 or BSD/386 contain trade secrets, I find that Plaintiff has failed to demonstrate a likelihood of success on the merits of its claim for misappropriation of trade secrets. No preliminary injunction will issue," the final judgement read.