Last part of the concept is the front end which is in charge of presenting the acquired data to the user. The actual form depends on the scenario. Possible front ends are web applications or stand-alone programs like the presented ARViewer. To identify the correct data by an AR application, the work piece or the machine must have a distinct feature. In the presented example, markers are used that can be tracked by the ARViewer. However, general information without a local reference can also be presented without the need of tracking.