I'd like a license restricting use to non-military projects, but otherwise just like the GNU GPL. (There is obviously no point in making a permissive license like that, because editing a comment is all it takes to create a derivative work and publish it under a different license. Right?)
Such a license will be very useful to have for authors with either of two concerns:
Support their business model via an additional income stream. In the best case there might eventually even be an app store, where defense contractors could readily purchase an alternative license subscription.
Prevent second-hand involvement in objectionable oil wars and other conflicts where smart plump generals get to play games of turning soldiers' lives into medals. (You can see I'm not a pacifist myself.) This seems also important now that deep learning and other AI are getting smart enough to enable research into truly horrible weapons, and it might be important to speed-limit smart weapon developments relatively to smart (and corruption-proof) surveillance ones (which is hard!)
The business model part is particularly interesting, because it avoids all the trouble with non-commercial licenses, while targeting a big market segment (over 3% of GDP). Also, military agencies don't hesitate on spending when it comes to software. So the ethics of this aren't as bad as it might seem at first sight. It's primarily about making the military pay for what they use. And they have the money.
This isn't a new idea. In 2006, there was some sort of an attempt by a team to add a vague non-military clause to their use of the GPL, which is of course not allowed, as the text of the license itself has not been set free. While their text tries to restrict usage to not
[...] harm any human being nor through inaction permit any human being to be harmed. This is Asimov's first law of Robotics.
I'm interested in something a lot more specific: "any project being conducted by or receiving direct funding from any of the agencies in the following list". And a long list of departments of defense of various countries.
In fact, this seems to be a frequently asked question, according to the FSF FAQ, and their position is clear: the GPL has nothing to do with this, end of story. No further pointers. The FSF has a page showcasing the Department of Defense and its use of free and open source software, with a clever pun on being "passionate about defending freedom". But that's fair enough, given DARPA's (indirect, yet crucial) involvement in FSF's roots. As nice as the idea of free (as in freedom) software is, some would rather emphasize ethics and kindness as superior ideals, whom freedom serves.
This article about CIA's Linux-powered killer drones mentions "several software licenses" that get criticized for being pacifist, but doesn't mention what those are. At any rate, I can't find them.
Is there actually already a license to this effect that has had proper attention from lawyers? If not, what is the best way to create it? Paraphrasing the GPL to circumvent its copyright is dangerous, because particular wording has magic meaning in courts of law. Perhaps there is a copyleft software license that allows restrictions to be added? Or is the reason why such a license doesn't already exist that there is some US legal mechanism that doesn't allow it? (But the DoD still has to honor Microsoft's EULAs, doesn't it?) If so, could the idea be worded in some other way to have a similar effect?
It occurred to me that the relationships between licenses could be like object-oriented programming. Just like patents talk about incorporating the content of another patent here by reference, I could write a short license that says "refer to the text of the GNU GPL", which will be provided separately verbatim, "except clauses X, Y, Z are not incorporated here, and we add clauses A, B, C." Is there any problem with this approach?
P.S. Please don't reiterate what the definitions of "open source" and "free software" are in the narrow sense. I am specifically asking about what I've outlined above, not something that meets those definitions (that would be contradictory indeed). In the broad sense, however, these licenses I'm seeking are both free and open source within the civilian population.