lambdamoo

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

LambdaMOO

   <games> The most frequently used {server} {software} for
   running a {MOO} and also the nerve-center (of sorts) of the
   MOO community.

   (ftp://ftp.lambda.moo.mud.org/pub/MOO/).

   {Telnet (telnet://lambda.moo.mud.org:8888)}.

   (1999-05-25)