qed is an ancestor of VI and unix ed.
Author: Ken Thompson Homepage: https://web.archive.org/web/20080214192028/cm.bell-labs.com/cm/cs/who/dmr/ Family: BellLabsFamily Platform: SDS 940, IBM 7094 at MIT CTSS, GE-645 Multics, GE-TSS License: Commercial
QED incomplete history: https://web.archive.org/web/20081020072055/http://cm.bell-labs.com/cm/cs/who/dmr/qed.html QED Implementation notes: https://web.archive.org/web/20150205030646/cm.bell-labs.com/cm/cs/who/dmr/qeddoc.html QED User's Manual: https://web.archive.org/web/20150205030634/cm.bell-labs.com/cm/cs/who/dmr/qedman.html QED as part of QEF https://web.archive.org/web/20190208192917/http://www.qef.com/html/toolsdesc.html
UTF8/Unicode-aware port of Rob Pike's QED editor for Unix: https://github.com/phonologus/QED