The state of the SCO case

The core of SCO's claim is that anything that IBM has ever allowed to be a part of a Unix system has become a "derived product" of Unix and must be treated as if it were Unix itself. SCO cannot make any ownership claims over this code - a side letter to the contract makes that explicit - but it does claim the right to keep IBM from disclosing its own code.

Through its public statements, SCO has since made claims of massive direct copying of SYSV Unix code into Linux. There is still no court case where SCO has made such claims, however. The company's experience at SCO Forum and subsequent public statements suggest that the evidence for direct copying of code - actual copyright violations - is weak at best. SCO might have a small case against SGI, depending on how a judge might choose to interpret the copyright status of 32V Unix and the true source of the ate_malloc() code. But that is between those two companies; the code in question has already been removed from current Linux kernels.

Increasingly, it seems that SCO is left with its original breach of contract case. The recently issued open letter from Darl McBride does nothing to change that impression; it mentions the ate_malloc() case but does not allege any other direct copying. Instead, the company's claims are expressed as follows:

In SCO's view, "Unix System V protected code" is a rather wider set than "SCO-owned code." In fact, at SCO Forum, the company put up a slide discussing the "more than one million lines" that it claims. Here's where they come from:

(SCO has posted the slides to its presentations on this page. You'll have to click past the cheery warning that things are optimized for Internet Explorer to view them, though.)

These claims are interesting in a number of ways. Let's look at the RCU claim for a moment. In a modern Linux kernel (RCU does not appear in 2.4), the RCU implementation is contained in two files (include/linux/rcupdate.h and kernel/rcupdate.c), which add up to an amazing 402 lines. That leaves us 44 files and 109,286 lines short of the claim made by SCO. Clearly, SCO must also be making claims on any code that uses RCU in any way. If you look for files that make any use of the RCU subsystem, the results are:

So, even with such an expansive interpretion of SCO's claim, there are 17 files missing. They must be big files as well, since they must account for the remaining 84,916 lines. The "contamination" caused by RCU is evidently a very broad thing. We asked SCO where the missing files were, but were told only "[T]his level of detail is something that we will save for our court case in 2005." So we're going to have to remain in suspense for a while. But one thing is clear: SCO claims that the old AT&T licenses give it amazing powers over code that has ever breathed the same air as SYSV Unix. Anybody who claims that the GPL is overly "viral" or that it threatens intellectual property should take a good look at the powers that SCO claims its license gives it. The GPL can't compete in that league.

SCO's legal argument is interesting; the company claims that Linux hackers have, while having never actually seen the SYSV Unix source, nontheless created a derived product of SYSV Unix. They are accused of copying something they never had access to. This argument seems destined to fail; how can something which contains no SYSV code be a derived product of SYSV? But that is the core of SCO's argument.

An interesting question comes out of this: what if SCO wins its case? SCO will have then convinced a court that IBM released IBM's code in violation of an agreement it had with SCO. The fact that IBM released IBM's code, however, would not change. SCO does not own that code, how can it claim a right to payments from Linux users? If SCO wins, it may get a chunk of money from IBM. But it should still have nothing which entitles it to license payment from Linux users.

Returning to Darl McBride's open letter, we note that there are no demands that Linux users buy SCO "licenses," and no threats of suits against users. Mr. McBride, instead, has taken a bit of a different approach:

One might point out that the free software world does, indeed, have an "intellectual property foundation." It is based on copyright law, and free licenses, including the GPL, which SCO has said it wants to break. One might also point out that the community is not in much of a mood for "working with" SCO at this point. But one's time might be better spent pondering what SCO was thinking when it published those words.

SCO clearly wants to be able to put a tax on Linux systems. SCO also clearly sees the GPL as an obstacle; there is no way to make a tax stick to Linux as long as it remains freely redistributable. Could SCO be casting around for a scheme to buy off free software developers should its challenges to the GPL fail? A nice tax for SCO and a few bones tossed to developers willing to relicense their code? It is hard to see how such a scheme could possibly succeed, but it is also hard to find another way to interpret the words quoted above.

In summary, the SCO case remains interesting. SCO has changed its tune several times, but, for the moment, is back where it began: a breach of contract suit against IBM. The company has yet to produce any evidence that Linux users owe it money. It is also now interested in "working with the open source community." But SCO remains unpredictable. We have not yet seen the last strange twist in this case.