QED (text editor)

QED is a string text editor developed by Butler Lampson and Peter Deutsch for the Berkeley Timesharing System , which runs on the SDS 940 . It was implemented by Peter Deutsch and Dana Angluin between 1965 and 1966 . ^{[1] [2]}

QED (from “quick editor” ^[3] ) turned to the use of teletype , but systems “for CRT displays [were not] considered, since many of their design considerations [were] completely different.” ^[4] Ken Thompson later wrote a version for CTSS ; This version is notable for the introduction of regular expressions . Thompson rewrote QED on BCPL for Multics . The Multics version was ported to the GE-600 system used by Bell Labs in the late 1960s with GECOS and later GCOS, after Honeywell took over GE's computer business. The GECOS-GCOS port used I / O routines written by AW Winklehoff. Dennis Ritchie , Ken Thompson, and Brian Kernigan wrote the QED guides used at Bell Labs. ^{[5] [6] [7]} Given that the authors were the main developers of the Unix operating system, it is natural that QED had a strong influence on the classic UNIX text editors: [ed]], sed, and their descendants, such as ex and sam , ^[8] and more remotely AWK and Perl .

A QED version called FRED (Friendly Editor) was written by Peter Fraser at the University of Waterloo for Honeywell systems ^[9] . The University of Toronto team, consisting of Tom Duff , Rob Pike , Hugh Redelmeyer and David Tilbrook, has implemented a version of QED that runs on UNIX ; David Tilbrook later incorporated QED into the QEF toolkit.

QED was also used as a text editor in the Norwegian Norsk Data systems, first Nord TSS, then Sintran III . It was implemented for the Nord-1 computer in 1971 by Bo Levendal, who, after working with Deutsch and Lampson at Project Genie and at Berkeley Computer Corporation, worked at Norsk Data (and later developed Nord TSS in 1971).