"If you go to this Groklaw article, you will find the rebuttal to it, and I'll add some new points here now. The memo points out similarities between Linux and UnixWare code, but it also pointedly stated that Swartz had not traced ownership of the code but would leave it to Mike Davidson to do that, since code in BSD Lite, he wrote, for just one example, would be perfectly legal to use in Linux:
"Additionally we investigated the settlement of The Regents of the University of California and BSDI. It is my understanding that anything in BSD Lite tape which was distributed by the University of California, is free of any legal encumbrances from SCO. Further any code which is necessary to meet the POSIX standard is also free of encumbrances.
"Swartz mentioned that it would take someone else to trace the ownership of the code that Swartz found that was similar, to find out if it was legally used or not. Mike Davidson later did in fact do the tracing out of each item on Swartz's list, and in 2002 he reported to Reg Broughton at Caldera, now calling itself the SCO Group, what he had found: that there was no illegal code in what Swartz had referenced in his memo. None. Here's the email [PDF], once again:"
