Just out of curiosity, I want to know opensource tools or projects that can add some interesting features to indie games, preferably those that could only be found on big-budget games.

EDIT: As suggested by The Communist Duck and Joe Wreschnig, I'm putting the examples as answers.

EDIT 2: Please do not post tools like PyGame, Inkscape, Gimp, Audacity, Slick2D, Phys2D, Blender (except for interesting plugins) and the like. I know they are great tools/libraries and some would argue essential to develop good games, but I'm looking for more rare projects. Could be something really specific or niche, like generating realistic trees and plants, or realistic AI for animals.

closed as not constructive by bummzack, Tetrad Feb 21 '12 at 17:08

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    Could we have a title change to just open source tools or something similar? I'm just wondering it could generate more interest with a more understandable title. – The Communist Duck Nov 18 '10 at 17:52
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    The benefit of putting them in as answers is that we can edit and vote on them as answers. That's the point of CW. – user744 Nov 18 '10 at 19:08
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    When he said it, I believe he meant individual answers. – Jesse Dorsey Nov 19 '10 at 0:54
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    I'm voting to close because this question is quickly degenerating into "list all the open source game libraries you know of". Even for CW lists, I'd prefer more focused questions; and CW lists should really have one answer per answer. – user744 Nov 19 '10 at 22:40
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    @Joe W.: I did my bit of research before putting my question over here. However, I wanted to hear other people's thought on the subject, rather than wander aimlessly through the Internet. Still, thanks for sharing your opinion. – Gastón Nov 20 '10 at 1:03

15 Answers 15

I think OpenGL and OpenAL are extremely obvious, but beyond that...


  • Bullet 3D Physics engine, used in AAA titles
  • Chipmunk Flexible and Powerful 2D Physics engine in straight C
  • Box2D Another robust and popular 2D physics engine
  • FPMath C++ template based math library, specifically for dealing with Fixed Point arithmetic (requires Boost)
  • OpenSteer Steering Behaviors for Autonomous Characters
  • Xiph home of lots of open source audio and video alternatives like Vorbis and Theora


  • Blender 3D Modeling Tool with a great deal of functionality and support for many different file formats
  • Gimp 2D Raster image manipulation, very robust feature set
  • Inkscape 2D Vector image manipulation, based on SVG
  • sfxr Sound effect generator, great if you're in a hurry or don't have an audio specialist
  • FFMpeg record, convert and stream audio and video


  • RakNet cross platform, open source, networking engine for game programmers (RakNet 4 is free for independent Developers that gross $50K or less)
  • Irrlicht open source high performance realtime 3D engine written and usable in C++ and also available for .NET languages.
  • Ogre3D One of the most popular open source game engines, and for good reason

Mobile Specific (since that's what I'm into at the moment)

  • Oolong game engine that includes much of the above mentioned, optimized for PowerVR on the iphone, maintained by Wolfgang Engel and Erwin Coumans of Grand Theft Auto fame
  • Cocos2D free Objective-C based iPhone specific port of the Python original, very easy to use and lots of community support
  • VFPMath Crazy fast math library written mostly with inline assembly to take advantage of the ARM processor
  • AndEngine 2D OpenGL Game Engine for Android

More Exotic:

  • Canonical Multitouch Gesturing system for all multitouch input devices and more
  • 1 dollar and N dollar stroke recognition systems. Links are for javascript implementations, but they have been ported to many other languages
  • OpenFoam Computational Fluid Dynamics (CFD) library in C++, see also FireFOAM an extension for modeling fire
  • Moody an n-Model body development framework I found interesting, primary usage would be Celestial Mechanics and Astrodynamics. Includes a viewer tool for files.
  • ofxMSAFluid Fluid dynamics simulation framework
  • Gromacs - "versatile package to perform molecular dynamics, i.e. simulate the Newtonian equations of motion for systems with hundreds to millions of particles"
  • Thanks slf, impressive list indeed, though I was aiming at more "exotic" libraries, targeting say AI or human motion. Physics libraries are good too, as long as they handle fluid and particles (and not just good ol' rigid bodies mechanics) – Gastón Nov 19 '10 at 21:50
  • added exotics :) – slf Nov 19 '10 at 22:36
  • Now, that's what I'm talking about ;D – Gastón Nov 20 '10 at 0:30

Recast & Detour is an awesome open source navigation mesh / path finding library. It's potentially got more appeal to larger titles than indie games, but I could definitely see it being useful to anyone wanting decent multi-agent movement in any 3D game.

The developer's (Mikko Mononen) blog also has several interesting entries around steering, path finding and navigation in general.

And it's actively maintained / developed.

  • Wow, nice library. I'll take a closer look at it. Thanks! – Gastón Nov 19 '10 at 12:56

I pulled some audio gems from my memory with help from Wikipedia.

Examples of tools/projects I found interesting are:

The following are blender tools:

ANT landscape generator: http://wiki.blender.org/index.php/Extensions:2.5/Py/Scripts/Add_Mesh/ANT_Landscape

Procedural generation of landscapes which simplifies the generation of complex terrain.

Blended Cities: http://jerome.le.chat.free.fr/index.php/en/city-engine/news/

Procedural city generation for the artist to quickly generate large cities. For my undergraduate dissertation I added city zoning to this: http://www.blendernation.com/2010/04/26/city-zoning-modification-for-blended-cities-script/

L-system tree generator: http://lsystem.liquidweb.co.nz/Examples/tabid/122/Default.aspx

Standalone vegetation generator: http://arbaro.sourceforge.net/

  • Wow, those are really nice ones... – Gastón Jan 13 '11 at 1:09
  • Ivy Complex vegetation generator
  • oops, sorry, the other ones weren't open source. Good editing. – S.gfx Jan 10 '11 at 15:42
  • Nice one, thanks – Gastón Jan 13 '11 at 1:08

It's a bit of an old topic but has some other recent posts, so I'm going to throw in my own voxel library. It's great for creating environment with smooth voxel terrain or 'cubic' environments like Minecraft. Environments can then be modified in real time and it should be easy to integrate with most 3D engines. It's under the zlib license for free for commercial use.

Have a look at http://www.thermite3d.org for more information.

  • Funny that you mention Thermite3D, just a couple of days ago I stumbled upon its site. Nice tool you've made! – Gastón Jan 15 '11 at 2:46
  • You should note that PolyVox has moved websites and is now at volumesoffun.com/polyvox-about – milliams Oct 25 '12 at 18:26

The Verse Protocol and reference Engine is astonishingly awesome; check out some discussion of a game made with the engine, and then ... the tools demos! The tools demos will blow you away....

  • Actually, too awesome to be true...I may have to check it out :) – Gastón Jan 15 '11 at 2:49

Here is a list of tools I found just today:

These two probably go without saying, but:

  • OpenGL (rendering)
  • OpenAL (audio)

are both high-quality industry staples that are open source and cross-platform. Always worth considering.

  • Thanks Nick, but those two are (besides totally awesome) quite...mundane, let say. I was gearing towards more "exotic" libraries. – Gastón Nov 19 '10 at 16:36

If you are interested in an innovative 3D framework, checkout Google's O3D that allows development of 3D games for WebGL compatible browsers, such as Chrome 9 (beta), Firefox's nighly build; Minefield & Safari WebKit (iPhone)

Checkout this video of the body browser made with this new technology if you don't yet have one of these browsers :)

I came across some tools for 2D game development recently that I find quite exciting:

  • SWFSheet converts a SWF created in Flash (including animations created using Actionscript) into a spritesheet or series of sprites
  • Zwoptex packs a series of sprites into a spritesheet and emits metadata about their position
  • Texture Packer is an alternative program which does the same

Personally, I think the Flash authoring tools are amazing and dearly miss them when I work in XNA or Java. Which is why I'm excited about giving the above a spin.

AnimKit is a small basic open source skeletal animation system with skinning, that loads the data straight from a Blender .blend file. It uses the liberal ZLib license, like Bullet.

The code is portable, it works under Windows, Linux, OSX and some iOS and Android samples are planned.

See http://code.google.com/p/gamekit/downloads/detail?name=animkit_src_r1020.zip and http://gamekit.org/forum/viewtopic.php?f=9&t=144

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