Openage is an open-source game engine that recreates the core functionality of Age of Empires II, built with C++20 and designed for cross-platform compatibility. It provides a foundation for real-time strategy game development with features like an entity-component-system architecture, OpenGL rendering, and multiplayer support. Developers can use it to study RTS engine design, contribute to an active game engine project, or build their own strategy games on top of the existing codebase.

215 open issues · last updated Jul 21, 2026