From The Free On-line Dictionary of Computing (8 July 2008) [foldoc]:
Sed
<tool, text> Stream editor.
The Unix stream editor. It has a powerful but cryptic
command language and is based on regular expressions.
There is a GNU version called GNU Sed.
[Jargon File]
(1994-11-03)
From The Free On-line Dictionary of Computing (8 July 2008) [foldoc]:
smoke-emitting diode
SED
<humour, electronics> (From "light-emitting diode") An
incorrectly connected diode, probably a {light-emitting
diode}, in the process of losing its magic smoke and
becoming a friode.
See also LER.
(1996-04-28)
From Jargon File (4.4.4, 14 Aug 2003) [jargon]:
SED
/S.E.D/, n.
[TMRC, from `Light-Emitting Diode'] Smoke-emitting diode. A friode
that lost the war. See also LER. [Not to be confused with sed(1),
the Unix stream editor. --ESR]