Adium is a popular free software instant messaging client for Mac OS X that supports multiple protocols through the libezv (for Bonjour) and the libpurple (all other protocols) libraries. It is written using Mac OS X's Cocoa API, and it is released under the GNU General Public License, and many other licenses for components that are distributed with Adium.

History

Adium was originally created by college student Adam Iser, and the first version, "Adium 1.0", was released in September 2001 and supported only AIM. The version numbers of Adium since then have followed a somewhat unusual pattern. There were several upgrades to Adium 1.0, ending with Adium 1.6.

At this point, the Adium team began a complete rewrite of the Adium code expanding it into a multiprotocol messaging program. The Adium team intended for this to be Adium 2.0. It was eventually decided that, due to the major differences between Adium 1.0 and the rewritten version, the entire program would be renamed "Adium X." The version numbering began with the version "Adium X 0.50" and continued through the released version Adium X 0.89.1. However, the team finally decided to change the name back to "Adium", and as such "Adium 1.0" was released on February 2, 2007.

The largest improvement in the new Adium was switching to libpurple to add support for IM protocols other than AIM; supported protocols now include ICQ, .NET Messenger Service, Yahoo!, and Jabber/XMPP (including Google Talk). Most of the work on libpurple itself is done by the Pidgin team; the Adium team mostly works on the Adium X GUI.

The development can be followed at Adium's trac page. The most significant change in Adium 1.0 was originally planned to be the switch from libpurple to joscar for implementing AIM, which would improve file transfer. However, the developers switched back to libpurple due to Apple's deprecation of the Java-Cocoa bridge.

Apple Inc. used Adium 0.89.1's build time in Xcode 2.3 as a benchmark for comparing the performance of the Mac Pro and PowerMac G5 Quad.

Protocols

Adium supports encryption through Off-the-Record Messaging. The left window shows messages as received by iChat, while the decrypted conversation can be seen on the right.

Adium supports the following protocols:

OSCAR including AIM, .Mac and ICQ services

Jabber including Google Talk and LiveJournal services

.NET Messenger Service, frequently known as "MSN"

Yahoo! Messenger, USA & Japan

Bonjour

MySpaceIM

Gadu-Gadu

Novell GroupWise

Lotus Sametime

Tencent QQ

MeBeam with a plugin

Tlen with a plugin

Xfire with the XBlaze plugin

Skype with a plugin

Plugins and customization

Adium makes use of a plugin architecture; many of the program's essential features are actually provided by plugins. The newest version includes support for file transfer, support for the Growl notifications system, Sparkle for program updates and support for encrypted messaging with the Off-the-Record Messaging library. Adium 0.88 was the first version compiled as a universal binary, allowing it to run natively on Intel-based Macs.

Adium is also highly customizable through the use of resources its developers call "Xtras". The program can be customized by the use of hundreds of third-party Xtras that alter the appearance of emoticons, Dock icons, contact list styles, and messages styles. Adium can also be enhanced through the use of different sound sets. AppleScripts can also be utilized to automatically alter behavior in responses to certain triggers.

Adium also used to have a fork project, called "Metal Adium". This version used iLife's "Brushed Metal" theme instead of the default Aqua and was maintained by Michael Barca and Andrew Nesbitt. It has been discontinued.