Legacy systems

thumb|A British Teletext Ltd. index page from September 2001, showing news about the [[September 11 attacks|255x255px]]

OS/2 (Operating System/2) is a proprietary computer operating system for x86 and PowerPC based personal computers created and initially developed jointly by IBM and Microsoft, under the leadership of IBM software designer Ed Iacobucci, intended as a replacement for DOS. The first version was released in 1987. A feud between the two companies beginning in 1990 led to Microsoft's leaving development solely to IBM, which continued development on its own. OS/2 Warp 4 in 1996 was the last major upgrade, after which IBM slowly halted the product as it failed to compete against Microsoft's Windows; u

Minitel, officially known as TELETEL, was an interactive videotex online service accessible through telephone lines. It was the world's first and most successful mass-market online service prior to the World Wide Web. It was developed in Cesson-Sévigné, Brittany, by government-owned France Télécom.

thumb|Videotex example screen showing its graphics capabilities, 1978. As in teletext, predefined, fixed-width graphics characters in multiple colors could be used to create an image. thumb|Minitel was perhaps the most successful videotex service worldwide, using this terminal, .

old computing technology or system that remains in use and may be out of date or in need of replacement

CHILL (an acronym for CCITT High Level Language) is a procedural programming language designed for use in telecommunication switches (the hardware used inside telephone exchanges). The language is still used for legacy systems in some telecommunication companies and for signal box programming.

thumb|right|TTX11 terminal, in this case being relabeled IBM PS/2. Teletex was ITU-T specification F.200 for a text and document communications service that could be provided over telephone lines. It was rapidly superseded by e-mail; however, the name Teletex lives on in several of the X.500 standard attributes used in Lightweight Directory Access Protocol.