Back in 1991, the sysops of the "STaTus BBS" in New Zealand created a #GUI for their board.
The system was powered by "Instant Graphics and Sound," a plain-text vector graphics scripting language for the Atari ST similar to RIPscrip, but predating it by several years.
Here's a video showing an IGS demo they made to give an idea of their impressive "GEM Desktop" #BBS interface:
