PESRJZBOH6PQSDPJ7SDJX52O65FMPEV4373YYEWZSF7ATXDQL2VAC
The license is GPL-2.0, meaning in particular that you can't relicense it under an incompatible license. Also, if you decide to make your own version of Pijul after looking at this code, this *is* derived work under copyright law, and you still have to respect this license.
The license is GPL-2.0.