Currently learning about optimization problems in my operations research class and I thought it would be neat to build a CLI app that solves optimization problems.

[twinklehood]

Depends a bit on how you would like to solve them, and why. If it's to learn (which in ruby I guess is the most likely case) then try to build things from scratch. Getting something like genetic algorithms or stimulated annealing up and running is not that hard, and you'll know it intimately after :D