That was my first GUI, on the Commodore 64 with RAM expansion (don't remember if I had the 128kb or 256kb expansion). I wrote and laid out my user group newsletter on GeoPublish. I felt like I was running a Mac.
I only know it existed because on Portugal, Phillips had an option to ship GeoWorks instead of Windows on their PCs, and a guy on our class was very adamant defending it.