[nigel_bree]

You'd likely find the experience pretty miserable, not so much because of the C compiler - Steve did a great job with that - but actually because of the filesystem. Coherent was around for a long time, remember; it used a very classic V6 UNIX filesystem, complete with odd endianness of 32-bit fields in the inode and most significantly, the classic 14-character file name length.

That right there will be an even bigger showstopper for the build scripts of most things than anything else. During the early 90's we could run GCC and Comeau C++ and all that kind of thing on Coherent fine because those codebases were still built for wide portability even though things like BSD FFS had opened that up - there were still plenty of machines running System III and System V code that most people took care not to create gratuitous collisions if truncation happened. Even shortly post the advent of Linux, that had changed dramatically and basically turned on its head and the effort involved in backporting to any flavour of classic UNIX (not just Coherent) quickly became almost impossible.