s&box is a modern game engine, built on Valve's Source 2
Open source library for N64 development
JavaScript-based game engine designed to empower developers
Descent 3 by Outrage Entertainment
Zoomable user interface (ZUI) with file manager, file viewers and more
Open and edit the archive files used in over 5700 games.
JavaScript framework to build game engines, games, emulators and apps
A c++ public domain audio output class
3D .NET engine for Windows, Linux, Mac
A pygame music lib.
A generic 2D engine for any kind of game
High-level C++ framework to ease game development
Pear3DEngine is a modern and modular 3D development framework