This article is from the alt.usage.english FAQ, by Mark Israel firstname.lastname@example.org with numerous contributions by others.
"Wired Style: Principles of English Usage in the Digital Age"
(ed. Constance Hale, HardWired, 1996, ISBN 1-888869-01-1) says:
"What's the plural of that small, rolling pointing device invented
by Douglas Engelbart in 1964? We prefer ~mouses~. ~Mice~ is just
too suggestive of furry little creatures. But both terms are
common, so take your pick. We actually emailed Engelbart to see
what he'd say. His answer? 'Haven't given the matter much
"In fact, Engelbart shared credit for the name with 'a small
group in my lab at SRI.' Nobody among his colleagues seems to
remember who first nicknamed the device, but all agree that the name
was given because the cord ('tail') initially came out the 'back' of
the device. 'Very soon we realised that the connecting wire should
be brought out the "front" instead of the back,' Engelbart notes,
but by then the name had stuck."
"The Microsoft(R) Manual of Style for Technical Publications"
(ed. Amanda Clark, Microsoft Press, 1995, ISBN 1-55615-939-0)
says: "Avoid using the plural "mice"; if you need to refer to more
than one mouse, use "mouse devices"."
Markus Laker reports from the U.K.: "In the early eighties, a
few people did selfconsciously say 'mouses', but the traditional
plural 'mice' gained ground rapidly and is now more or less