Adium

Adium provides a free, open‑source instant messaging client for macOS, allowing users to connect to a variety of services such as XMPP (Jabber), IRC, and many others through the libpurple protocol library. It presents conversations in tabbed chat windows with a themeable WebKit message view, and integrates directly with the macOS Contacts app to merge accounts into unified contacts. The client supports visual notifications via Growl and macOS Notification Center, OTR encryption, file transfer, and a range of third‑party extensions (Xtras) for further customization.

The software is built with the Cocoa API, released under the GNU GPL, and is maintained by volunteer contributors on GitHub. It offers translations into 27 languages and a sophisticated events system for handling status changes and alerts. Documentation includes extensive articles and troubleshooting guides, and users can seek support through IRC channels.

Adium runs on macOS 10.7.5 and newer, with older versions supporting earlier macOS releases. It does not host any messaging services itself; it functions solely as a client that connects to external IM networks.