share and enjoy!

from Jargon File (4.4.4, 14 Aug 2003)

Share and enjoy!
 imp.

   1. Commonly found at the end of software release announcements and
   {README file}s, this phrase indicates allegiance to the hacker ethic
   of free information sharing (see {hacker ethic}, sense 1).

   2. The motto of the complaints division of Sirius Cybernetics
   Corporation (the ultimate gaggle of incompetent {suit}s) in Douglas
   Adams's Hitch Hiker's Guide to the Galaxy. The irony of using this as
   a cultural recognition signal appeals to hackers.

from The Free On-line Dictionary of Computing (8 July 2008)

Share and enjoy!

   1. Commonly found at the end of software release announcements
   and {README files}, this phrase indicates allegiance to the
   hacker ethic of free information sharing (see {hacker ethic}).

   2. The motto of the Sirius Cybernetics Corporation (the
   ultimate gaggle of incompetent {suits}) in Douglas Adams's
   "Hitch Hiker's Guide to the Galaxy".  The irony of using this
   as a cultural recognition signal appeals to {freeware}
   hackers.

   [{Jargon File}]