Open Source real-time strategy game engine for early Westwood games such as Command & Conquer: Red Alert written in C# using SDL and OpenGL. Runs on Windows, Linux, *BSD and Mac OS X.

One framework for creating powerful cross-platform games.

Unity3D Client And C# Server Framework

Entitas is a super fast Entity Component System (ECS) Framework specifically made for C# and Unity

Stride (formerly Xenko), a free and open-source cross-platform C# game engine.

Flax Engine – multi-platform 3D game engine

The Open Toolkit library is a fast, low-level C# wrapper for OpenGL, OpenAL & OpenCL. It also includes windowing, mouse, keyboard and joystick input and a robust and fast math library, giving you everything you need to write your own renderer or game engine. OpenTK can be used standalone or inside a GUI on Windows, Linux, Mac.

Murder is a pixel art ECS game engine.

A ROS/ROS2 Multi-robot Simulator for Autonomous Vehicles

Open source reimplementation of GTA San Andreas game engine in Unity

QQ Group：538722494，KSFramework = KEngine + SLua(or xLua) , Unity3D Framework/Toolsets focus on hot reload

A game framework written with osu! in mind.

Pixel Vision 8's core philosophy is to teach retro game development with streamlined workflows. PV8 is also a platform that standardizes 8-bit fantasy console limitations built on top of the open-source C# game engine based on MonoGame.

OpenSAGE is a free, open source re-implementation of SAGE, the 3D real time strategy (RTS) engine used in Command & Conquer: Generals and other RTS titles from EA Pacific. Written in C#. Not affiliated with EA.

a 2D Game Development Framework

A .NET ascii/ansi console engine written in C# for MonoGame and SFML. Create your own text roguelike (or other) games!

Svelto ECS C# Entity Component System

.NET bindings for Direct3D12, Direct3D11, WIC, Direct2D1, XInput, XAudio, X3DAudio, DXC, Direct3D9 and DirectInput.

A constantly evolving array of Unity C# components for 2D games, including classes for pixel art cameras, events & messaging, saving & loading game data, collision handlers, object pools, and more.

Entity Component System framework aiming for syntax and usage simplicity with maximum performance for game development.