Late 80s to early 90s before Linux existed there weren't many ways to run unix on x86 hardware of the time. I remember desperately searching for solutions so I could have unix at home and not always rely on the university SunOS/HP-UX/AIX machines.
SCO was one player in this space. I can't remember the other one I was considering.. In the end they were all too expensive for poor-student-me so didn't use any of them and kept using the lab SunOS boxes via 2400bps dialup from home until Linux appeared on the scene.
Coherent was my first exposure to PC "Unix", back when I was in high school. I had a 386SX laptop with 4 megs of RAM. It was amazing how lightweight Coherent was. The manual was also amazing, very comprehensive, including most of the POSIX APIs.
SCO was one player in this space. I can't remember the other one I was considering.. In the end they were all too expensive for poor-student-me so didn't use any of them and kept using the lab SunOS boxes via 2400bps dialup from home until Linux appeared on the scene.
https://en.wikipedia.org/wiki/Santa_Cruz_Operation