EVENNIA  [codebase]
A Python framework rather than a finished game. Two Evennia games can have
nothing in common but the plumbing.
https://www.evennia.com/

Games we have identified as running this codebase
  11 listed, 0 archived
  /games?codebase=Evennia
  Measured in their handshakes: GMCP, MCCP, MSDP, MSSP, MXP

Evennia is a MU* framework, not a game — which is the first thing to know about
it and the thing that makes comparing Evennia games to each other unhelpful. It
is a Python library built on Django and Twisted that gives you accounts,
objects, rooms, commands, a persistence layer and the network stack, and then
expects you to write the game.

The consequence is that "runs Evennia" tells you far less about a game than
"runs PennMUSH" does. There are combat MUDs on Evennia and there are roleplay
games on Evennia and they share no vocabulary. Two Evennia games may not have a
single command in common.

For a developer who already knows Python this is the shortest path from nothing
to a running world, and it is where a good share of new games since the
mid-2010s have started.

WHAT IT LOOKS LIKE FROM OUTSIDE

Evennia offers MSSP, and it publishes a player count through it. On the game we
measured it also negotiated MCCP2 — compression — which is characteristic of a
stack that took its telnet seriously.

Because Evennia is a framework, what a given game negotiates is partly the
game's decision. The adoption figures on the protocol pages are counts of what
servers actually offered us, not of what the framework can do, and for Evennia
those two are further apart than for most.

See also
  AresMUSH — /reference/codebases/aresmush
  You want collaborative roleplay — /reference/collaborative-roleplay
  GMCP — /reference/protocols/gmcp