SCO and SGI

During the SCO Forum 2003, The SCO Group (SCO) showed several alleged examples of illegal copying of copyrighted code in Linux. The open source community quickly debunked most of the examples shown, but one example showed that code from Unix was indeed used in some of SGI's Linux contributions. The Linux maintainers claim that the code in question was in fact already removed from Linux before the example was revealed, not because it was infringing, but because the code in question duplicated functions that were already present in Linux. SGI and other analysts also responded to this matter and claimed that the code in question was not infringing at all.

Background

During the SCO Forum, held on August 17 – 19, 2003, SCO publicly showed several alleged examples of illegal copying of copyright code in Linux. Up till that point, these examples were only available to people who signed an NDA, which prohibited them from revealing the information shown to them. SCO claimed the infringements are divided into four separate categories: literal copying, obfuscation, derivative works and non-literal transfers.

The example used by SCO to demonstrate literal copying is also known as the "atemalloc" example. While the name of original contributor was not revealed by SCO, quick analysis of the code in question pointed to SGI. At this time it was also revealed that the code was already removed from the Linux kernel, because it duplicated already existing functions.

Within hours, the open source community started several different analyses of the infringing code. While the results of these analyses differ slightly, they all confirm that the code in question was derived from Unix code Fact|date=June 2008. These analyses also pointed out that whilst the code could possibly have originated in Unix, this does not necessarily prove infringement of copyrights.

As it turned out this was a particularly bad example, because the code in question was never used in the mainstream distributions of Linux, it was only present in the IA-64 version. There are not many systems currently in the marketplace which are based on this CPU. Combined with the limited time in which the code was present in Linux, it makes the chance of actually encountering a system running this code very slim.

The origin of the code

While it is possible that the code contributed to Linux originated from UNIX System V, its original implementation happened in the early 1970s. Comparison of the original Unix source code and the UNIX System V source did not reveal any substantial differences between the two. In fact Dennis Ritchie, one of the creators of the original versions of Unix, acknowledged that either he or Ken Thompson wrote the original code from which the UNIX System V code is derived:

:"So: either Ken or I wrote it originally. I know that the comments that first appeared by the 6th edition were definitely written by me, since I spent some time annotating the almost comment-free earlier editions."

This is very important, because the original versions of Unix did not have any copyright claim in the source code. At that time the law required these copyright claims which effectively means the early Unix code is not protected by copyright law. Additionally, both Santa Cruz Operation and The SCO Group released the source code to these early versions of Unix under a BSD-like license, allowing the use of the source code in other open source products.

GI responds

October 1, 2003, SGI responded to SCO’s allegations in an open letter to the Linux community. In this letter, Rich Altmaier, vice president of software, claims that these small code fragments were indeed inadvertently included in the Linux kernel:

:"All together, these three small code fragments comprised no more than 200 lines out of the more than one million lines of our overall contributions to Linux. Notably, it appears that most or all of the System V code fragments we found had previously been placed in the public domain, meaning it is very doubtful that the SCO Group has any proprietary claim to these code fragments in any case."

ee also

*SCO-Linux controversies
*USL v. BSDi

External links

* [http://www.lemis.com/grog/SCO/code-comparison.html SCO's evidence of copying between Linux and UnixWare]
* [http://www.catb.org/~esr/writings/smoking-fizzle.html SCO's Evidence: This Smoking Gun Fizzles Out]
* [http://perens.com/Articles/SCO/SCOSlideShow.html Analysis of SCO's Las Vegas Slide Show]
* [http://oss.sgi.com/letter_100103.txt Open letter from SGI to the Linux community]