openDesktop.org - The website openDesktop.
Google ARCore - Google Augmented Reality SDK
SourceForge - The Complete Open-Source and Business Software Platform.
Vuforia SDK - Vuforia is a vision-based augmented reality software platform.
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.
Wikitude SDK - Wikitude’s all-in-one AR SDK combines 3D tracking technology (SLAM), image recognition and tracking, as well as geo-location for apps.