Non-free dependencies

From FreeGameDevWiki

There are many useful game libraries that non-free in the "free as in freedom" sense but are freeware or shared source. These libraries however are not free software and depending on them can be a problem to users and developers.

Contents 1 Philosophy 2 Non-free libraries 2.1 Audio 2.2 Network 2.3 Physics 3 Solution 4 Projects using non-free libraries 5 Success stories 6 References

Philosophy

Non-free libraries need to be avoided to allow users and developers to be able to stay free of proprietary software when using a game/engine or to get the software included in official distribution repositories, that have strict open-source policies.

From the FSF FAQ question "Can I write free software that uses non-free libraries?":

If you do this, your program won't be fully usable in a free environment. If your program depends on a non-free library to do a certain job, it cannot do that job in the Free World. If it depends on a non-free library to run at all, it cannot be part of a free operating system such as GNU; it is entirely off limits to the Free World.

The FAQ also warns of possible legal issues arising from non-free library use.

Non-free libraries

Audio

• BASS
• FMOD
• IrrKlang

Network

• RakNet

Physics

• Newton Game Dynamics, including OgreNewt

Solution

Use free (as in freedom) game libraries.

If a non-free dependency is already in place, make it optional (allow to compile without sound/networking).

Projects using non-free libraries

Some non-free libraries became popular in open source games.

• Dakar 2010 - Newton
• Impulse - IrrKlang
• Mark IV - FMOD, RakNet
• monster 2 - BASS
• Open Game Engine - RakNet
• Those Funny Funguloids! - FMOD (OpenAL SI patch available)
• Trinity Reign - RakNet

Success stories

Project that moved away from non-free libraries.

• DungeonHack - FMOD, Newton (to Alure and Bullet) ^[1]
• Game Editor - RakNet^[2]

References

1. ↑ Non-free libraries thread on DungeonHack forums
2. ↑ RakNet thread on Game Editor forums.