Atlantis, originally released in 2006 by Riverdark Studios, is a great quality MOO client built using Cocoa, so it feels more like a true OS X application than any other Mac client out there. It supports ANSI colors, scrollback (with automatic locking!), command history, custom notepad for each character, external edit windows and a host of other features Sindome doe not make use of (or are against the rules). For more information about Atlantis, you can visit its homepage at riverdark.net/atlantis.
World Name: Sindome Hostname: moo.sindome.org Port: 5555 Login as: Your character name Password: Your current password
By default, Atlantis tries to use '/' for its own purpose. Sindome uses this key for cyberware, so if you get implants, you need it. In the General section of the Preferences, check 'Aliases do not require leading /' to solve this problem.
The default keys for scrolling through the list of commands you've sent are ctrl-p and ctrl-n. If you're like me, you'd rather have that on your up/down arrows instead. Open up the Hotkeys section of the Preferences to change these settings.