Linux kernel developer Christoph Hellwig today filed a lawsuit against VMware (NYSE:VMW; US$36 billion market cap) due to their long time refusal to observe the terms of the GPL when incorporating code by Hellwig into their kernel, which remains proprietary. If VMware observed the GPL’s terms, their kernel including all source would be released under the GPL. This is a significant case, in part due to the rarity of GPL enforcement lawsuits. Details on the website of Software Freedom Conservancy, which is coordinating and funding (you can help) this action.

If the GPL is rarely enforced, its differentiation from non-copyleft licenses such as MIT, BSD, and Apache is muted. Why should you support license differentiation and thus GPL enforcement?

1. You think copyleft is a wonderful hack, a productive and even necessary strategy for protecting and expanding the software commons. No enforcement makes the hack buggy: rarely executing and easily circumvented. So of course you want enforcement.
2. You think copyleft curtails freedom, and ironically hampers the software commons — intractable incompatibility means software can’t be freely mixed, and the attempt to prevent capture by proprietary software interests only abets capture of the field by intellectual parasite lawyer interests. Your efforts to persuade developers and companies that they should avoid GPL software at all costs (up to reimplementation) in preference to permissive and public domain instruments can only be enhanced by prominent GPL enforcement by lawsuit.
3. You think copyleft is great for software business, as one can acquire users by offering GPL software, then acquire customers by shaking down users who could conceivably not be observing the GPL to the letter. Public GPL enforcement makes your salespeople more compelling.

Among people who have any opinion about copyleft, I’m pretty sure there are very few who accept more than one of the above thoughts. I enjoy all three (the third looks like a sin tax to me). My point here is that people who completely disagree on the purpose and efficacy of copyleft ought all be excited and supportive of copyleft enforcement. But there are additional, less commonly discussed reasons:

4. You think strong copyleft encourages more people to release free software, people who would not be comfortable with releasing under a non-copyleft license, whether because they fear piracyproprietarization more than obscurity (some overlap with 1 above), or because they want to make wealthy entities pay (lots of overlap with 3 above). Strong copyleft serves as the NonCommercial of the software world (without being fundamentally broken like NC, though the most radical believers in 2 above might disagree) in that it increases the range of licensing options to meet the preferences of both those who fear exploitation by business, and those who want to exploit business. Strong copyleft isn’t so strong without enforcement, so anyone who understands the value of this differentiation should want it to be strengthened by enforcement actions.
5. You think copyleft-for-x is needed for some non-software field (or hear such thoughts expressed; e.g., for seeds or hardware designs, even real property), but the details of how copyleft works are a bit fuzzy. Enforcement by lawsuit is where the rubber meets the road, so you should enjoy the demystification provided by such actions and support them. Also, successful copyleft enforcement will stoke more people to have desires for copyleft-for-x, thus increasing your community of people intent on figuring out the “for-x” part.
6. You think copyleft is most usefully considered as a prototype for and test of rules that ought be enforced by more effective regulatory mechanisms. Whether you think software provided without source and permissions should be totally banned, not regulated at all, or only regulated for particular uses or in particular fields (e.g., products and services already subject to other safety, disclosure, and pro-competition or consumer protection requirements), it is absurd to think that developer whim and resources in applying and enforcing the GPL regulates and regulates effectively an optimal set of software. It is time to move beyond debate of a hack of state-deputized private censorship as central to software freedom politics and policy, and on to debating directly state vs. market regulation of software (with all the usual arguments about (in)adequacy of market provision and harm/help of state intervention) as in any field of importance, preferably with very strong commons-favoring bias from both sides (e.g., software freedom market-skeptics and state-skeptics ought agree that regulation by private censorship, which serves proprietary interests almost exclusively, be wound down, and that state entities self-regulate by mandating software freedom for everything they acquire and fund). Unenforced copyleft means the rules prototyped are untested, reducing salience of the prototype, so you also should enjoy GPL enforcement actions.

I enjoy these latter 3 reasons especially, perhaps especially because few other people seem to (I’m eager to be or become wrong about this).

Go help Software Freedom Conservancy support Hellwig’s enforcement against VMware, or tell me why I’m wrong. Note I’m on Software Freedom Conservancy’s board and endorse all of their work, but as usual, this blog post represents only my opinion. Of the reasons to support enforcement above, they’d agree with 1; probably find 2 and 3 and maybe 4 objectionable; 5 and 6 perhaps curious but distant from work in today’s trenches. Again, my point is that many more people than those who agree with 1 (copyleft for good), even those who totally disagree with 1, should enjoy and support GPL enforcement.

The lawsuit will probably be heavily covered in the technology press, but you can read some early discussions now at LWN.net, Hacker News, and reddit. You can also read about copyleft in general at copyleft.org (another Software Freedom Conservancy project; my take).