Minverva is a MacOS X based IRC client that does everything which is documented in the IRC protocol.

Features:

-Compact interface: Have all your channels in one window, or one window for every channel.
-Optional Floating Taskbar lists all open chat windows for quick switching.
-Custom command aliases: Create your own command shortcuts using the built in command alias system.
-Custom contextual menus: Define what you want on your userlist menu .
-Nickname Autocomplete: Start typing a nick and press the tab key. Minerva show a list of closest matching nicknames, or just complete the nick if there's only one match.
-Custom definable message formats: Everyone likes their channel text formatted differently. Minerva lets you decide.
-Text / HTML Channel Logging: Why should your logs be less formatted then your output?
-Individual channel settings: Every channel remembers it's own settings, so when you come back the next day the window opens right where you left off.
-XDCC Tracker: For those who hang out in XDCC file sharing channels, Minerva offers a XDCC Tracker which catalogs all the file bot offerings.
-URL Tracker: Need a URL that someone said an hour ago? Don't scroll up, just look in the tracker.
-iChat Style IRC Buddylist: Floating window shows all your IRC buddies for each open network, and shows their status.

New in this version:
-Added /dns command to do a quick server name lookup
-Fixed problem with sending messages to recognized users via query windows
-Added Connections menu item to preferences button on the main taskbar.
-Removed the Connections button from the main taskbar
-Improved speed of userlist sorting
-Fixed a crash that occurred when userhost information is received.
-Double clicking a hostmask or nickname in the Friend Recognition dialog now edits it
-Added buttons to the Friend Recognition dialog to remove hostmasks, nicknames, or entire entries.
-Userlist now marks recognized friends by underlining them. If the user is not OPed or Voiced, a dot will appear next to their name.
-Whois and user Get Info now recognize buddies
-Added Friend Recognition Settings to the Application menu
-Fixed an exception error that occured when renaming a Friend Recognition entry
-See complete release notes.