Godot Engine – Multi-platform 2D and 3D game engine

Phaser is a fun, free and fast 2D game framework for making HTML5 games for desktop and mobile web browsers, supporting Canvas and WebGL rendering.

Dear ImGui: Bloat-free Immediate Mode Graphical User interface for C++ with minimal dependencies

Bitmap & tilemap generation from a single example with the help of ideas from quantum mechanics.

🎮 A list of popular/awesome video games, add-ons, maps, etc. hosted on GitHub. Any genre. Any platform. Any engine.

CRYENGINE is a powerful real-time game development platform created by Crytek.

Cross-platform, graphics API agnostic, "Bring Your Own Engine/Framework" style rendering library.

🎮 📝 A list of Game Development resources to make magic happen.

A retro game engine for Python

One framework for creating powerful cross-platform games.

🎮 A step-by-step guide to implementing SSAO, depth of field, lighting, normal mapping, and more for your 3D game.

Data-oriented and data-driven game engine written in Rust

Fast and lightweight WebGL game engine

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

Gaming meets modern C++ - a fast and reliable entity component system (ECS) and much more

A statically typed lisp, without a GC, for real-time applications.

a fresh & lightweight javascript game engine

Lightweight and modular C++11/C++14 graphics middleware for games and data visualization

(ARCHIVED) Rant – The all-purpose procedural text library

A hand-crafted 2D game library in Go

gamedev blog

A Curated List of Game Network Programming Resources

2D skeletal animation runtimes for Spine.

Stride Game Engine (formerly Xenko)

A fast, scalable, distributed game server engine/framework for C++, include the actor library, network library, can be used as a real time multiplayer game engine ( MMO RPG/MOBA ), which support C#/Lua script/ Unity3d, Cocos2dx and plan to support Unreal.

A curated list of Game Boy development resources such as tools, docs, emulators, related projects and open-source ROMs.

Dependency Injection Framework for Unity3D

🎮 GDevelop is an open-source, cross-platform game engine designed to be used by everyone.

Powerful, mature open-source cross-platform game engine for Python and C++, developed by Disney and CMU

pygame (the library) is a Free and Open Source python programming language library for making multimedia applications like games built on top of the excellent SDL library. C, Python, Native, OpenGL.