Open OSCAR Server 是一个用 Golang 编写的开源即时消息服务器，兼容经典 AIM 和 ICQ 客户端。该项目独立开发，与 AOL 或 Yahoo! Inc. 无关。支持从 AIM 1.x 到 7.x，TOC1 和 TOC2 协议客户端，以及从 ICQ 98x 到 5.x 的多种版本。功能包括即时消息、好友列表、聊天室、公共和私聊、用户资料、隐私控制、在线状态、离线消息和局域网及直接连接文件共享。The server offers quickstart guides for Linux (x86_64), macOS (Intel and Apple Silicon), and Windows 10/11 (x86_64). Users without AIM or ICQ installed can follow dedicated client setup guides. The project is under active development and welcomes contributions.

A Discord server is available for community support and involvement. Administrative tasks can be managed via a Management API with endpoints for listing, creating, and deleting users, changing passwords, listing active sessions, and creating or listing public chat rooms. Commands are provided for both PowerShell (Windows) and curl (macOS/Linux/FreeBSD).

Open OSCAR Server is licensed under the MIT license, making it freely available for self-hosting and modification.