StarLink from 1984: Digital Research's Forgotten Multiuser PC Experiment
Starlink from 1984

In 1984, Digital Research Inc. launched StarLink, a hardware and software combo to turn IBM PCs into multiuser systems using Concurrent DOS. Despite offering a cheaper alternative to dedicated minicomputers, the product failed commercially due to high total costs and the inability to run Lotus 1-2-3, the dominant application of the era.
"What it could not run was the application that made the IBM PC dominant: Lotus 1-2-3."