William Stein, founder of SageMath, writes about open source math software, SageMathCloud, and the business side of open source projects.
Commenters cite it for his account of why Sage was built against closed tools like Magma, his views on open core licensing, and a pricing gripe.
Possible donate the credits to an open source project?
I suggest contacting @williamstein [0] who has been actively seeking help to fund Sage Math Cloud [1]. See post here [2] and here [3] for reference.
I'm living on credit cards -- I have no NSF grant support anymore, and SageMathCloud is still losing a lot of money every month, and I'm unhappy about this situation. It was either completely quit working on SMC and instead teach or consult a lot, or lose tens of thousands of dollars. I am doing the latter right now. I was very caught off guard, since this is my first summer ever to not have NSF support since I got my Ph.D. in 2000, and I didn't expect to have my grant proposals all denied (which happened in June). [3]
[0] https://news.ycombinator.com/user?id=williamstein
[1] https://cloud.sagemath.com/
[2] https://news.ycombinator.com/item?id=10175563
[3] http://sagemath.blogspot.com/2015/08/react-flux-rethinkdb-and-sagemathcloud.html
For an excellent description of another instance of this sort of issue, see [1] about Canonical and Mir.
Github seems to have things pretty figured out: they have a closed core that they control, with a veneer of hackability, and a lot of hype. You then get people to work for you for free by having them create plugins that, while open source, are effectively controlled by Github, Inc.
The key thing is to make people feel that they're contributing to a community, even though that community doesn't really have ownership of the work. By the time the tension between the community's needs and Github's needs comes out, you've already locked everyone into your ecosystem.
Other notable instances of this phenomenon include the MAGMA computer algebra system, and the creation of SAGE (see [2]).
[1]: http://mjg59.dreamwidth.org/25376.html
[2]: http://sagemath.blogspot.ca/2009/12/mathematical-software-and-me-very.html
The GNU Affero GPLv3 has been a recurring topic during RethinkDB's existence, but I cannot substantiate the same having been an issue for MongoDB. Links appreciated.
Some instances of people asking about GNU Affero GPLv3 and RethinkDB:
(2014-11-16) https://github.com/rethinkdb/rethinkdb/issues/3347
(2015-06-16) https://groups.google.com/forum/#!topic/rethinkdb/g5UEck3sqMs
(2016-10-10) https://sagemath.blogspot.com/2016/10/rethinkdb-must-relicense-now-what-is.html
(2017-01-09) https://github.com/rethinkdb/rethinkdb/issues/6221
I believe that Sage was modeled after Magma, which isn't important, but I highly recommend this long blog post by William Stein[1] talking about his motivations, the problem of basing academic work on closed source software, and in the case of Magma, the potential politics of even being able to get the software.
[1] http://sagemath.blogspot.com/2009/12/mathematical-software-and-me-very.html
There is an excellent blog by the creator of Sage:
http://sagemath.blogspot.it/2014/08/you-dont-really-think-that-sage-has.html
Sage is absolutely amazing, but it is very far behind the cutting edge CAS systems (MAGMA/Mathematica) - I think he is being a bit harsh in his assessment, but he has incredibly ambitious goals - and by those goals, he has fallen short.
dmytton you have done a FANTASTIC job on your pricing page (https://www.serverdensity.com/pricing/)! I just got screwed by DataDog's confusing pricing page (http://sagemath.blogspot.com/2016/07/datadogs-pricing-dont-make-same-mistake.html). Your's is the ultimate example of what to do right. WOW.