The license is definitely not compatible with the GPL but also not a free
software license either:
III.1.d doesn't allow to charge for the software. Per the FSD, "Free
software" does not mean "noncommercial". A free program must be available for
commercial use, commercial development, and commercial distribution.
Commercial development of free software is no longer unusual; such free
commercial software is very important. You may have paid money to get copies
of free software, or you may have obtained copies at no charge."
Plus, that section requires you to distribute the software to the general
public. It should be possible to keep the software to yourself and only
distribute it to the people you want to (like those that pay you money.)
