This repository contains the source code for the Poseidon game engine, which powers the remastered version of Arma: Cold War Assault (CWR). It is a large, monolithic C++20 codebase with a modular subsystem architecture covering graphics (OpenGL 3.3), audio (OpenAL), networking (UDP with custom transport), input (SDL), AI, world simulation, UI, and asset management. The engine supports dedicated servers, modding via PBO archives, and a scripting language (SQF/SQS). The repository also includes a suite of CLI tools (PBO packing, image conversion, model inspection, etc.), a Blender addon for importing P3D models, and Rust components for a master server and test harness (Trident). Extensive unit tests (Catch2) and fuzz harnesses are provided. The codebase is a locked snapshot with no active development, but it demonstrates high craftsmanship in areas like custom containers, memory management, and network protocol design. However, it suffers from technical debt including heavy use of preprocessor macros, global state, and platform-specific conditionals.