I believe they are all free for academic use. There is also SCIP, one of the fastest academic solvers but you also need a license for commercial use, although I think the license is much cheaper than CPLEX and Gurobi.
I work at a non-profit and not a University, so I can't use them for free.
My very nice, but slightly used car cost me less money and it has been driven over an hour per day for 7 years. That makes those solvers very hard for me to justify outside of production where the license costs are worth every darn penny.
> I work at a non-profit and not a University, so I can't use them for free.
What’s required to qualify for an academic license? Could you split your nonprofit into a business aspect, and then a walled-off research aspect (funded by the business aspect) that by itself fits the definition of academia by which these companies judge?
Or, more simply, could your nonprofit partner with a University on R&D, with the University acquiring a license to the solver and then retaining you as a project volunteer (on loan from your nonprofit) to use the solver?
Presumably, one difference in both cases is that the output of the solver would need to be published in the form of a scientific paper, as well as being used in your nonprofit’s development.
Several of the solvers require that you have an academic email (or even IP) adress. If you don't but still think you qualify, I guess one would need to contact them and go through some work-around, possibly every year to renew?
I totally agree. But if you are a non-profit you might be able to get a SCIP license for free, you just have to contact the people behind it. But if a moderate performance improvement is not that important for you then GLPK is definetly the best option.
My very nice, but slightly used car cost me less money and it has been driven over an hour per day for 7 years. That makes those solvers very hard for me to justify outside of production where the license costs are worth every darn penny.