Telidon

Telidon (from the Greek words τῆλε, tele "at a distance" and ἰδών, idon "seeing") was a videotex/teletext service developed by the Canadian Communications Research Centre (CRC) during the late 1970s and supported by commercial enterprises led by Infomart in the early 1980s. The CRC referred to Telidon as a "second generation" system, offering improved performance, 2D color graphics, multi-lingual support and a number of different interactivity options supported on various hardware. With additional features added by AT&T Corporation, and 16 other contributors in North America and supported by the Federal Government, Telidon was redefined as a protocol and became the NAPLPS standard.

Initially in multiple tests, Telidon failed to demonstrate compelling functionality, and the auxiliary equipment costs remained high. Although projects like GRASSROOTS for the Province of Manitoba, SOI for Venezuela, Compuserve, LA Times in California, EPIC for General Motors, NOVATEX for Teleglobe Canada and the Swiss PTT nationwide application, demonstrated the concepts, eventually government support for the project ended on 31 March 1985, and the various commercial services based on it closed shortly thereafter.

Telidon saw limited use after that, in niches like informational displays in airports and similar environments. NAPLPS did appear in several other products, notably the Prodigy online service and some bulletin boards. Telidon had a more lasting legacy on the hardware side; its NABTS communications system found re-use years later in WebTV for Windows.

Herb Bown is widely considered to be the "father" of Telidon. Bown had been working in the computer graphics field since the late 1960s, originally using plotters but later moving to video systems. Starting in 1970, Bown and a team at the CRC started working on a "Picture Description Instruction" (PDI) format to encode vector graphics information. An interpreter, the "Interactive Graphics Programming Language" (IGPL), read the PDI codes and rasterized them for display. By this time the team consisted of Bown, Doug O'Brien, Bill Sawchuck, J.R. Storey and Bob Warburton.

...
Wikipedia