If you really don’t want to spend money, there’s always GNU Octave. Sure, it doesn’t have the thousands of matlab toolboxes, but if you’re running code from 40 years ago it shouldn’t need those anyway. I wrote a couple of scripts recently and then rewrote them slightly so that they would be compatible with octave.
Cataclysm: Dark Days Ahead. Zombie survival roguelike, forked from the original cataclysm by whales. Also check out Cataclysm: Bright Nights which is a fork of CDDA that makes it more gamey like the original, and less like you’re playing 2d arma.