Now that the server is down, I’ll be looking into providing the server and client as a single package so that players can still play the game as a standalone product. Since CUO was meant to be a multiplayer extension of Ultima I through Ultima IV, I don’t yet know if it’s possible to complete any of it without other players. The Ultima I dungeons were populated with many more monsters, and Ultima III and IV are inherently designed to have companions. Perhaps I’ll add a switch for standalone mode that would allow classic companions to join, or possibly add hireling tech? I’ll also be publishing the source and game assets to either GitHub or Bitbucket soon, so that interested parties can fork the project if desired.
UPDATE: The stand-alone server and client downloads are now available!