openDesktop.org - The website openDesktop.
Aurasma - Aurasma is changing the way we interact with the world. Turn everyday objects, images, and places into new opportunities for engagement through striking augmented reality experiences. Watch Video. The World's Leading Augmented Reality Platform .
SourceForge - The Complete Open-Source and Business Software Platform.
ViewAR - ViewAR combines all available tracking systems like Vuforia, Wikitude, visionLib, allowing to build AR applications as easy never before.
Freecode - Freecode (formerly known as Freshmeat) is one of the legit open source development platforms that will be the key for developers and programmers to have a streamlined process via having enhanced collaboration and coding leverages.
ARToolKit - The world's most widely used tracking library for augmented reality.