I surely have used it, during 1996 - 2000.

Thanks to Oberon I learned what is possible to achieve with GC enabled systems programming languages, it was this experience to lead me to play archeology on our library, Usenet, gopher, FTP,.. and discover what the world of programming languages outside Bell Labs actually like.

Young pupil fell astray from UNIX church never to look into it again with the same wonder.