Colloquy is an open-source IRC

Internet Relay Chat

Internet Relay Chat is a protocol for real-time Internet text messaging or synchronous conferencing. It is mainly designed for group communication in discussion forums, called channels, but also allows one-to-one communication via private message as well as chat and data transfer, including file...

, SILC

SILC (protocol)

SILC is a protocol that provides secure synchronous conferencing services over the Internet.- Components :...

, ICB

Internet Citizen's Band

Internet Citizen's Band is an early Internet chat program. It was released in 1989.- History :The first version of ICB was a program called "Forumnet" or "fn", written by University of Kentucky IT staffer Sean Carrick Casey...

 and XMPP

Extensible Messaging and Presence Protocol

Extensible Messaging and Presence Protocol is an open-standard communications protocol for message-oriented middleware based on XML . The protocol was originally named Jabber, and was developed by the Jabber open-source community in 1999 for near-real-time, extensible instant messaging , presence...

 client for Mac OS X

Mac OS X

Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...

. Colloquy uses its own core, known as Chat Core, although in the past it used Irssi

Irssi

Irssi is an IRC client program for Linux, Microsoft Windows, and Mac OS X. It was originally written by Timo Sirainen, and released under the terms of the GNU General Public License in January 1999.-Features:...

 as its IRC protocol engine. One of the primary goals behind Colloquy was to create an IRC, SILC and ICB client with Mac OS X visuals. Colloquy contains a user interface

User interface

The user interface, in the industrial design field of human–machine interaction, is the space where interaction between humans and machines occurs. The goal of interaction between a human and a machine at the user interface is effective operation and control of the machine, and feedback from the...

 that follows Apple's Human interface guidelines

Human Interface Guidelines

Human interface guidelines are software development documents which offer application developers a set of recommendations. Their aim is to improve the experience for the users by making application interfaces more intuitive, learnable, and consistent. Most guides limit themselves to defining a...

 in addition to containing support for traditional IRC command-line controls such as /nick and /join.