Piosolver is so expensive (pro version is about $1000) so I decide to write a opensource,free version of it. I already check it's preformance and result with piosolver and I believe it's a good competitor.
My idea is the free version has some drawbacks:
(1) people don't want to pay will stick with this free version
(2) it's like a sample pack for solver, you may download the free version and say "it's not so good after all". Bad for business
(3) it increase the probability of been hacked