When I got to University (1998) the Computer Science lab had SunOS on Sparc workstation. My first time using Unix. Computer Science was mostly taught in C and you would have to do all of your work on the lab because Windows didn’t cut it.  Then we discovered Linux (Slackware on 13 disks) and could do work from our dorms. Then one day I submitted code that worked on my machine bit completely crashed on the Professors. This is when I learned that Unix was big endian and Linux was little endian and that matters for things like memory operations. Our favorite Professors would let you submit either as long as you told them which one to run it on.

I think technology it was Sparc vs 386 and not specifically a Unix vs Linux thing. It was a long time ago!