This is definitely a place for an attorney with expertise in software law (which I am not). But I can offer this practical advice -- don't sell the software to

This is definitely a place for an attorney with expertise in software law (which I am not). But I can offer this practical advice -- don't sell the software to the university, sell it to their students. Retain the rights to the software, and offer a reasonable retail price to each student. If you instead sell the software to the university once, they will sell it to the students over and over and make the money you should have made.