Teletext systems network in the mid-late 1970s. Due to the adoption of a common teletext standard (WST), the ORACLE system ceased in 1976. The name was retained for the service itself, that continued after that year using the WST standard. "World System Teletext" (or "WST") is the name of a standard for teletext throughout Europe today. Almost all television sets sold in Europe since the early ’80s have built-in WST-standard teletext decoders as a feature. It originally stems from the UK standards developed by the BBC (Ceefax) and the UK Independent Broadcasting Authority (ORACLE) in 1974 for teletext transmission, extended in 1976
Teletext systems of standard teletext in 1991. The CBC ran a teletext service, IRIS, accessible only in Calgary, Toronto and Montreal. It ran from 1983 until about 1986, and used the Canadian-developed Telidon system, which was developed in 1980. Like Antiope, Telidon allowed significantly higher graphic resolution than standard teletext. Adoption in the United States was hampered due to a lack of a single teletext standard and consumer resistance to the high initial price of teletext decoders. Throughout the period of analogue broadcasting, teletext or other similar technologies in the US were practically non-existent, with the only technologies resembling such existing in