[planb]

I‘m a proponent of MIT and BSD style licenses normally, but this calls for something like AGPL: Allow other researchers and engineers to improve upon your code and build amazing things with it. If someone wants to use your work to earn money, let them understand and reimplement the algorithms and concepts, that’s fine too.

[kragen]

That's probably not viable under US copyright law, especially with the Bright Tunes Music v. Harrisongs Music precedent; if someone is going to reimplement the algorithms and concepts without a copyright license, they're better off not reading your code so they don't have to prove in court, to a computer-illiterate jury, that the aspects their code had in common with your code were really purely functional and not creative.