The Jargon File (version 4.4.7, 29 Dec 2003):

Berkeley Quality Software
 adj.

    (often abbreviated ?BQS?) Term used in a pejorative sense to refer to
    software that was apparently created by rather spaced-out hackers late at
    night to solve some unique problem. It usually has nonexistent, incomplete,
    or incorrect documentation, has been tested on at least two examples, and
    core dumps when anyone else attempts to use it. This term was frequently
    applied to early versions of the dbx(1) debugger. See also Berzerkeley.

    Note to British and Commonwealth readers: that's /berk'lee/, not /bark?lee/
    as in British Received Pronunciation.


The Free On-line Dictionary of Computing (30 December 2018):

Berkeley Quality Software
BQS

    (Often abbreviated "BQS") Term used in a pejorative
   sense to refer to software that was apparently created by
   rather spaced-out hackers late at night to solve some unique
   problem.  It usually has nonexistent, incomplete, or incorrect
   documentation, has been tested on at least two examples, and
   core dumps when anyone else attempts to use it.  This term was
   frequently applied to early versions of the "dbx(1)" debugger.

   See also Berzerkeley.

   [Jargon File]

   (1996-01-15)