ZeroMQ

Licensing and Ownership

The project SHALL use the GPLv3 or a variant thereof (LGPL, AGPL).

I’ve already explained how full remixability creates better scale and why the GPL and its variants seem the optimal contract for remixable software. If you’re a large business aiming to dump code on the market, you won’t want C4, but then you won’t really care about community either.

All contributions to the project source code (“patches”) SHALL use the same license as the project.

This removes the need for any specific license or contribution agreement for patches. You fork the GPL code, you publish your remixed version on GitHub, and you or anyone else can then submit that as a patch to the original code. BSD doesn’t allow this. Any work that contains BSD code may also contain unlicensed proprietary code, so you need explicit action from the author of the code before you can remix it.

All patches are owned by their authors. There SHALL NOT be any copyright assignment process.

Here we come to the key reason people trust their investments in ØMQ: it’s logistically impossible to buy the copyrights to create a closed-source competitor to ØMQ. iMatix can’t do this either. And the more people that send patches, the harder it becomes. ØMQ isn’t just free and open today—this specific rule means it will remain so forever. Note that this is not the case in all GPL projects, many of which still ask for copyright transfer back to the maintainers.

The project SHALL be owned collectively by all its Contributors. ...