This software is heavily commercial and as this really not free.
${PORTDIR}/licenses/solve contains only information how to obtain a license, but doesn't list any conditions. Anyway, the question is if the license must have been read by the user to be legally binding. If not, then we need not do anything here (because any license not listed under @FREE is non-free by definition).
Jeremy just told me to do so. There no further license as this. I know that it isn't a "license" as it should be, I cannot get any other. To run the software you need to have the valid license key. Therfore I think the installation is for free, but the usage not.
I think that we need not do anything here.