My favorite non-X-windows GUI was NeWS.
It had some good capabilities not found elsewhere.
It had some good capabilities not found elsewhere.
https://news.ycombinator.com/item?id=22456575
There are a lot more interesting DonHopkins comments in this thread:
That is the part of NeXT that many miss, and it also has in common with SunOS/NeWS, the UNIX compatibility was only the bottom layer, the cool parts were above it.