Game Engines with Source: Learning from the best

As a game developer, I'm always intrigued by how other people do things and what solutions have been developed to some problem. As well as the big ones, many smaller engines are being worked on and I find myself downloading repositories, compiling, tinkering and marveling at what's available. This is a non-exhaustive list of game engines whose source code you can freely inspect, compile, run and learn from.

NB: When I say game engine I am referring to a conglomerate of technologies that generally has an editor, a scene description, input/output, etc. If the scope is more limited we would be talking about a rendering or a physics engine.

NB2: Notice I say public source, and not open or free or anything that suggests that you can arbitrarily make use of the code. Every entry in the list has its own licensing terms, commercial options and/or conditions that you need to abide by.

Team Engines

Engines that are being developed by teams of individuals, generally are well established and have commercial products behind them.

	Engine	Source	Screenshot
	Unreal Engine	https://github.com/EpicGames/UnrealEngine
	CryEngine	https://github.com/CRYTEK/CRYENGINE_ReadMe
	Godot	https://github.com/godotengine/godot
	The Forge	https://github.com/ConfettiFX/The-Forge
	Torque 3D	https://github.com/GarageGames/Torque3D
	Flax Engine	https://github.com/FlaxEngine/FlaxEngine
	Panda 3D	https://github.com/panda3d/panda3d
	Armory 3D	https://github.com/armory3d/armory
	NeoAxis Engine	https://github.com/NeoAxis/NeoAxisEngine
	Urho3D	https://github.com/urho3d/Urho3D
	PlayCanvas Engine	https://github.com/playcanvas/engine
	Lumberyard	https://github.com/aws/lumberyard
	O3DE	https://github.com/o3de/o3de
	ezEngine	https://github.com/ezEngine/ezEngine
	Defold	https://github.com/defold/defold
	Cocos Creator	https://github.com/cocos/cocos-engine
	Stride	https://github.com/stride3d/stride
	Dagor	https://github.com/GaijinEntertainment/DagorEngine

Solo Engines

Engines that are being developed generally by a single individual or at most a handful. Some are commercial products, others are often either experimental or toy pieces of tech.

	Engine	Source	Screenshot
	Raylib	https://github.com/raysan5/raylib
	Wicked Engine	https://github.com/turanszkij/WickedEngine
	Hazel	https://github.com/TheCherno/Hazel
	Spartan Engine	https://github.com/PanosK92/SpartanEngine
	Pax Engine	https://github.com/pmbittner/PaxEngine3
	Acid Engine	https://github.com/EQMG/Acid
	rbfx	https://github.com/rokups/rbfx
	nCine	https://github.com/nCine/nCine
	Lina Engine	https://github.com/inanevin/LinaEngine
	VQE	https://github.com/vilbeyli/VQE
	ET Engine	https://github.com/Illation/ETEngine
	Overload	https://github.com/adriengivry/Overload
	Mocha	https://github.com/mocha-engine/mocha
	Esoterica	https://github.com/BobbyAnguelov/Esoterica
	RBDoom3BFG	https://github.com/RobertBeckebans/RBDOOM-3-BFG
	Lumix Engine	https://github.com/nem0/LumixEngine
	Ethereal Engine	https://github.com/volcoma/EtherealEngine
	Lumos Engine	https://github.com/jmorton06/Lumos
	Sir Engine	https://github.com/giordi91/SirEngineThe3rd
	PathFinder Engine	https://github.com/man-in-black382/PathFinder
	Thunder	https://github.com/thunder-engine/thunder
	Crown Engine	https://github.com/crownengine/crown
	Hyperion	https://github.com/krait-games/hyperion-engine
	VXR	https://github.com/avilapa/vxr
	AdriaDX12	https://github.com/mateeeeeee/Adria-DX12
	Hybrid	https://github.com/Angelo1211/HybridRenderingEngine
	Koala Engine	https://github.com/phisko/kengine
	Halley Engine	https://github.com/amzeratul/halley
	Explosion Engine	https://github.com/ExplosionEngine/Explosion
	Banshee Engine	https://github.com/ValtoGameEngines/Banshee-Engine
	LiteFX	https://github.com/crud89/LiteFX

Rendering Engines

These are only the graphics part of an engine but mature enough and well developed that their code is worthwhile to learn from.

	Engine	Source
	Diligent Engine	https://github.com/DiligentGraphics/DiligentEngine
	bgfx	https://github.com/bkaradzic/bgfx
	Ogre 3D Next	https://github.com/OGRECave/ogre-next
	Methane Kit	https://github.com/egorodet/MethaneKit
	Magnum	https://github.com/mosra/magnum
	Vultaik	https://github.com/FaberSanZ/Vultaik
	Veldrid	https://github.com/mellinoe/veldrid