Open OSCAR Server

Open OSCAR Server is an instant messaging server written in Go that speaks the protocols used by classic AIM and ICQ clients. It lets enthusiasts bring old messaging software back to life on their own network, and the project is independent and not affiliated with or endorsed by AOL or Yahoo.

On the AIM side it supports a range of Windows clients from versions 1 through 7, buddy lists and icons, away messages, chat rooms, profiles, privacy controls, warnings, directory search and file sharing, plus TOC1 and TOC2 protocol clients such as gaim and TiK. For ICQ it covers Windows clients from the late 1990s to the mid-2000s, with instant messaging, profiles, user search, presence statuses and offline messages.

The server is released under the MIT licence and is run by you, with quickstart guides for Linux, macOS and Windows plus client setup guides for AIM and ICQ. Pidgin can also connect to it. The project is non-commercial and under active development, so it suits hobbyists, retrocomputing communities and anyone running a private legacy-compatible chat.