Open 3D Engine (O3DE) is an Apache 2.0-licensed multi-platform 3D
Cross-platform 2D and 3D game engine with modular architecture
Free game engine for development of desktop, mobile, and web games
A modular Common Lisp game engine
Java/JavaFX/Kotlin Game Library (Engine)
scene-oriented, flexible 3D engine (C++, Python, C#, Java)
Stride (formerly Xenko), a free and open-source cross-platform C# game
GLScene Engine for Delphi & C++Builder VCL Windows 32/64
Amateur 3D Game Engine
Game library for Pascal
The multiplayer game engine
Source port of Doom, Heretic, Hexen and Strife developed in Delphi
Vivid is a modern C++ 3D engine using OpenGL4+
3D C++ Game Engine - yet another open source game engine
A tool to generate Tree sprites and voxels for the Doom game
A tool to generate Rock sprites, models and voxels for the Doom game
A tool for creating voxels for the DelphiDoom Engine
Data-oriented and data-driven game engine written in Rust
Conceptual design of Light Fixed Wing Aircraft
MD2 (Quake2) Model Viewer
Duke Nukem 3D Map Viewer
Portal Adventure - The hunt for Dr. Freak
realistic truck & car simulator, with OpenGL graphics
Advanced Numeric Puzzle Game