1) Corporate spin-off 
Viewtron was an online service offered by Knight-Ridder and AT&T from 1983 to 1986. Patterned after the British Post Office`s Prestel system, it started as a videotex service requiring users to have a special terminal, the AT&T Sceptre. It began to be offered on IBM, Apple and Commodore computers as home computers and other personal computers bec....