I studied ecology, and first semester maths was done by a professor who only accepted our homework if it was coded in GNU Octave.
That was a fun learning experience for most of us who went into it with no computer background.
His (as it later turned out, correct) reasoning was that Matlab is a standard tool in Geosciences, but he didn't want to require us to buy it, so we're using the free alternative that can be installed on any Linux system.
It was my first Linux experience, and I got hooked. In my bachelor's thesis I coded a 3D simulation of groundwater movement, and afterwards I ended up in IT instead of ecology.