I still laugh at Breadbox Ensemble 4.x, tho the GEOS for IBM PC was head of MS, but seriously 4.x released in 2001? not a littlebit late?
I remember trying GEOS for IBM, still have a copy somewhere. It was very resource friendly (ran on a 8088?). I was far more impressed with its design philosophy than I was with Windows 3.x. Unfortunately, it was completely proprietary and difficult to get it to front the whole world of non-GEOS software.
Had the authors made it compatible with all existing software, computer history might be very different today.