3D

Amp II
A 3D Game Design System that provides fast scene rendering with per pixel lighting, bump mapping, specular highlighting and stencil shadowing used to create stunning real time graphics.
http://www.4drulers.com/amp.html

Antiryad Gx
Cross platform 3d engine with embeded Basic language (Gel Basic) compiler. [Freeware]
http://www.arkham-development.com/

Aztica 6DX 3D Engine
A DirectX 3D engine for Windows that can be used with C++, Java, Delphi and Visual Basic.
http://sourceforge.net/projects/aztica/

Chris Hecker/Texture Mapping
Perspective Texture Mapping by Chris Hecker
http://www.gamers.org/dEngine/quake/papers/checker_texmap.html

3d engines programming in Java and MS-DOS
Information on programming various types of 3D engines (raycasting, indoor, landscape) in Java and MS-DOS. Source code available.
http://www.geocities.com/siliconvalley/campus/5009/

3D GameStudio
Create 2D and 3D games using a visual interface and a JavaScript style programming language. Latest versions includes support for pixel and vertex shaders, physics and high-quality rendering.
http://www.conitec.net/english/gstudio/

3D Graphic Engines List
A list of free and commercial graphics engines.
http://cg.cs.tu-berlin.de/~ki/engines.html

3D Graphics Math
A mathematical overview of computer graphics starting with model space and advancing down the graphics pipeline through world space, all the way to device space.
http://cs.fit.edu/~wds/classes/graphics/

3D Graphics Pattern Recognition
Programming projects in OpenGL and Java3D that demonstrate artificial intelligence and pattern recognition useful in 3D games programming.
http://www.geocities.com/cohvi/projects.htm

3D Rad
A programmable, user-friendly, 3D real-time engine which allows you to build interactive 3D worlds by simply placing animated and intelligent 3D objects into a virtual scenery.
http://www.3drad.com/

Desgraff
Tutorials on OpenGL and 3D Studio Max, links to games programming resources, home site of the Decoy3d Engine.
http://www.desgraff.com/

Developing UTF & DGL Technology Presentation
Project description and goals, the objective is to build a game engine, that makes easy to program any kind of 3D game, on Visual C++ and OpenGL.
http://drg.com.sapo.pt/dgraph/index.html

Diesel Engine
An OpenGL Quake3 Arena Map Viewer, written in c++. It supports a variety of features including volumetric fog, portals/mirrors, items, basic entities, skyboxes/cloudlayers, videotextures and multitexturing for up to 6 texture units. [Open source, GPL]
http://diesel.n5home.net/

3DzzD
A Web 3D engine using Java 1.1 technologie.
http://dzzd.net/

Excession Software.com
OpenGL based 3D wargame construction kit
http://www.peter.co.nz/

G3D
A C++ 3D graphics library for game developers, researchers, and students. [Open source, BSD License]
http://g3d-cpp.sourceforge.net/

Golgotha Forever
the game, and I4, the game SDK.
http://golgotha.sourceforge.net/

Havok
Software development kit for PC, PS2, and Mac.
http://www.havok.com/

Java Monkey Engine
A 3D game engine written in and for Java. Many features including collisions, particle systems, shaders, terrain system, renderer abstraction.
http://www.jmonkeyengine.com

NeoEngine
A 3D game engine (C++). [Open source, MPL]
http://www.neoengine.org/

Obsidian
An open source 3D virtual world for Linux and OpenGL.
http://old.zog.net.au/computers/obsidian/

Opale.Soya
High-level, object-oriented 3D engine designed for 3D games in Java. Uses GL4Java to access native OpenGL. [Open Source, LGPL]
http://savannah.nongnu.org/projects/opalesoya/

Phil Frisbie's Programming Page
My personal 3D game programming pages. You will find several past and present projects, most with full source code.
http://www.geocities.com/SiliconValley/Lakes/7220/

Power Render 3D Engine
Powerful 3D engine that combines indoor BSP and outdoor terrain levels. Includes Windows based tools and editors using DirectX 8's latest features. [Commercial, w/ demo]
http://www.powerrender.com/

Programming Multimedia and 3D in Realtime
SouthGreece - the OpenGL Trender implementation; Trender SDL - a software-only realtime renderer of 3D Studio files; Earth - a Linux renderer that uses Voodoo cards to show a simple model of the earth and the sun; 3DEnvMap - a Real-time 3D Renderer with Gouraud-Shaded Environment Mapping.
http://www.softlab.ece.ntua.gr/~ttsiod/

QuakeForge
A 3D graphics game engine based on id Software's legendary Quake and QuakeWorld game engine.
http://www.quakeforge.net/

Ray Game Designer
Freeware 3D construction kit for Windows based on a RayCaster.
http://eicart.free.fr/rgd/

Revolution3D-Engine
3D game engine. It uses DX9, and has 3D, 2D, Mouse, Joystick, Keyboard support.
http://www.revolution3d.net

sbdev
A series of tutorials on raycasting and 3D Programming without a 3D API.
http://www.sbdev.pwp.blueyonder.co.uk/

Simpren
3D renderer DLL based on the Direct3D. [Only for testing]
http://simpren.tripod.com/

Subshock HQ
The headquarters of the Subshock 3D Games programming group.
http://www.tekscode.com/

Superfluxus Media
A 3D audio tool, used to arrange sound spatially allowing new ways of audio programming. It is mainly based on Direct3d Sound and the EAX technology of Creative. Extra feature: space morphing.
http://www.superfluxus.de/

Sylphis 3D
A 3d game engine, that supports per pixel lighting and shadows along with realistic physics.
http://devnet.sylphis3d.com

Touchdown Entertainment
Tool set for developing 3D applications for the PC, Sony PlayStation 2 and Microsoft Xbox.
http://www.touchdownentertainment.com/

Truevision3D
A 3D Engine, Media Engine and Net Engine for 3D game and application development using any major programming language.
http://www.truevision3d.com/

World Foundry
A 3D level game engine. Originally a commercial product, now released under the GPL. Designed from the beginning to be cross-platform, runs on windows, working on linux port.
http://tenetti.org/cgi-bin/twiki/view.cgi/WorldFoundry/WebHome