wxWidgets - wxWidgets: Cross-Platform GUI Library
Google ARCore - Google Augmented Reality SDK
Electron - Build cross platform desktop apps with web technologies
8th Wall - Cross-Platform Mobile AR
GTK - GTK+ is a multi-platform toolkit for creating graphical user interfaces.
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.