PenPoint OS
（重定向自PenPoint）
The PenPoint OS was a product of GO Corporation and was one of the earliest operating systems written specifically for graphical tablets and personal digital assistants. It ran on AT&T Corporation's EO Personal Communicator as well as a number of Intel x86 powered tablet PCs including IBM's ThinkPad 700T series, NCR's 3125, 3130 and some of GRiD Systems' pen-based portables. It was never widely adopted.