On mobile devices such as smartphones or tablets, so called Augmented Reality (AR) browsers provide a computer-supported, extended reality by displaying relevant information in the user's environment. Such information can be shown in a list, a map, or even embedded in the real environment. In the latter case, the generated overlay of typical AR-browsers on e.g. a smartphone or tablet computer has to be aligned with the real world. This can be done using geotags for object and GPS and compass for the AR-device.
RADAR offers an open social media system for contributing, managing, and sharing arbitrary geocontents from different sources such as the social and semantic web and digital libraries. By using the respective adapters, geocontents managed within RADAR can be used in augmented reality browsers.