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 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, Telidon became the basis for the NAPLPS standard.
In multiple tests, Telidon failed to demonstrate compelling functionality and the equipment costs remained high. Government support for the project officially 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.