Holy cow, I wrote a book!
Once upon a time, there was a team developing two versions of
the first a short-term project to ship soon, and the other a more
ambitious project to ship later.
They chose to assign the projects
Ren and Stimpy,
in honor of the lead characters from the
eponymous cartoon series.
Over time, the two projects merged,
and the code name that stuck was Ren.
When the project came up in a meeting with Bill Gates,
it was mentioned verbally but never spelled out,
and since Bill wasn't closely tuned into popular culture,
he mapped the sound
/rɛn/ not to the hairless Mexican dog
but to the Christopher Wren,
St. Paul's Cathedral.
In follow-up email, he consistently referred to the
project by the name "Wren".
The Ren team liked the fact that their name gave the boss
the impression that the project
was going to be a masterpiece of architectural beauty,
so they never told him he got the name wrong.
Even though it has nothing to do with the story:
The project in question is the one that
eventually became known to the world as Outlook.