KlayGE is a cross-platform open source game engine with plugin-based architecture.

Tiny OpenGL Wrapper / 3D Engine in C++

A Cool High Performance Game Engine

A port of Babylon.js to C++

HXEngine is a cross-platform open source game engine developed by personal

lunokWatch (lilygo twatch2020 series)

Vulkan-based graphics framwork designed for game development and graphics applications on Linux.

3D Graphics Engine For Games | C++ OpenGL 4.1

Brakeza3D is a OpenSource Engine3D for old school lovers

Neta from <NEW GAME!> Sakura Nene's game engine.

A path tracer based on hardware ray tracing

3D game engine written in C++

Open Source OpenGL C++ Engine

A fast and modern vulkan based rendering engine

Vulkan Render Engine

HevEn is a small FPS/TPS game engine (for test purposes)

Graphics Framework (engine) with modular architecture

3D graphics rendering engine

UNMAINTAINED: Please have a look at the vulkan-renderer

A component based 3D game engine writen in C++