A small text based game engine (VB.Net)
A roguelike game engine/editor
Component 2D Game Engine
A basic 3D environment with a first-person POV
A point-n-click adventure game engine for GameMaker: Studio
WGFX 2D Game Engine
Scripting language of the hawk game engine
Framework for a graphical point and click adventure game in Java
Advanced 2D/3D(CPU,GPU) Game Engine Library
A complete 2D Game Engine with built in drag and drop editor
A DirectX based graphics/physics engine
Free MMORPG Engine. Develop and host graphical browser-based games.
A simple WinAPI game engine