Open Source Objective C Messaging Platforms

Adium is an Open Source, multi-protocol instant messaging application for Mac OS X. Adium supports AIM, ICQ, Jabber, MSN, Yahoo!, Google Talk, Bonjour, Gadu-Gadu, Novell Groupwise, SIP/SIMPLE (Text), and Lotus Sametime. Additionally, it supports all of these applications at once so, even if you have multiple IM accounts, you don't have to log into each account separately.

Instant messenger client for GNUstep. Using Björn Giesler's port of the AddressBook framework, Angelos accesses the user's addressbook to produce a buddylist with real names and photos.

Azonto is a Cross-Platform Mobile Messaging Application that allows users to share images, songs, videos, create and add each other to groups. It is for the trendy who wants to be on top of the mobile messaging game.

Fire is a multi-protocol instant messenger client for Mac OS X based on freely available libraries for each service. Currently Fire handles AOL Instant Messenger®, ICQ®, MSN® Messenger, Jabber, limited IRC, Yahoo!®, and Apple Bonjour communications.

WeChatExtension-ForMac is an unofficial plugin that enhances the WeChat desktop experience on macOS by adding new features such as message anti-recall, multi-instance login, auto-reply, and UI customization. Designed for users who want more control and functionality from their desktop WeChat client, this plugin requires patching the app and may violate WeChat’s terms of service.

WeChatPlugin-MacOS is an unofficial plugin for the macOS version of WeChat, providing features like auto-reply, message anti-recall, and remote control. It injects custom functionality into the official WeChat client using macOS’s dynamic library loading, offering power-user features not present in the native app. This project has been widely used but is no longer actively maintained due to security and compatibility concerns.