Had Linux not happened, most likely I would still be deploying Solaris into production.
Solaris is dying because of Linux coming into the scene and Sun's mismanagement, being bought by Oracle that most cares about Unbreakable Linux, this wouldn't have happened in an alternative universe without Linux.
Plus it was only one example of UNIX, others could be given that were affected in similar ways.
FreeBSD, OpenBSD and others are surviving, hardly getting any upstream changes from Apple, Sony or plenty of others that take profit of the license, beyond some charity whenever they feel like, this isn't thriving.
It is no surprise that all POSIX clones competition against Linux on the IoT space, by those vendors not keen in upstream updates for Android, are using MIT/BSD and Apache licences.
Maybe this isn't up to my standards, yet it is what I believe.
Is there a non-gnu c compiler? I could only find: https://github.com/386bsd/386bsd/tree/2.0/usr/src/usr.bin/gc...
People tend to forget that Linux was a small project that provided a gpl kernel for the GNU system - not the other way around (hence GNU/Linux, Android/Linux, GNU/kFreeBSD etc).
Honestly by the late 1990's Linux was what was being requested by a lot of employers, with Solaris being the most common system it was displacing (in my experience). BSD simply wasn't even on the radar for most employers/employees.
386BSD (of which FreeBSD is based) is an independent lineage to GNU and was released under the BSD licence. Thus also independent to GPL. In fact for a period in the early to mid 90s, it was BSD which was used as the free "UNIX" with Linux seen largely as a hobbyist platform and Hurd little more than a pipe dream.
Linux might have since become the dominant POSIX server platform but to argue that GPL was the saviour of open source is a gross misunderstanding of the history of open source (and UNIX).
The reason Linux "won" was ironically because it was seen as more of a hacker OS. It was used more by kids because it was more fun to hack around with. Those hackers then grew up, got proper jobs in IT and continued to use what they were already experienced in...Linux.