TINYMUSH  [codebase]
The ancestor of the MUSH line, still running games. It taught this crawler that
its own negotiation bytes can break the next command it sends.
https://github.com/TinyMUSH/TinyMUSH

Games we have identified as running this codebase
  9 listed, 0 archived
  /games?codebase=TinyMUSH
  Nothing was offered in any handshake we have read from them.

TinyMUSH is where the line PennMUSH, TinyMUX, RhostMUSH and CobraMUSH all
descend from, and it is still deployed. Development is quiet rather than absent.

WHAT IT LOOKS LIKE FROM OUTSIDE

No MSSP. A pre-login WHO that answers with a sentence of the form 0 Players
logged in, 22 record, no maximum.

THE BUG IT FOUND IN US

TinyMUSH is worth a paragraph here because it is the game that exposed a defect
in this site's own crawler, and the correction is a good illustration of what
"measured" is supposed to mean.

Our probe read TinyMUSH as count unknown for weeks. The guess on file was that
its reply had no trailing newline. It does. Captured off the wire, the real
cause was ours: TinyMUSH does not parse telnet at its login screen, so the three
bytes of IAC DO MSSP we send on connect land in its input buffer as though
somebody had typed them. The next line it reads is not WHO but three control
bytes followed by WHO, which is not a command it has — so it redisplays its
connect screen and says nothing about players.

The probe now sends a bare newline after negotiating and discards whatever that
produces, because that output is a reaction to bytes we chose to send and is
therefore neither the game's connect screen nor its answer. TinyMUSH reads
correctly now, and the probe finished in a third of the time.

A directory that had not checked would have published "this game does not report
its players" for as long as it existed, and the sentence would have been about
us.

See also
  PennMUSH — /reference/codebases/pennmush
  TinyMUX — /reference/codebases/tinymux
  MUSH, MUD, MUCK, MOO — what the words mean — /reference/mush-mud-muck-moo