SkyscrapAR helps software programmers to understand the java source code using a building metaphor displayed using augmented reality technology with fiducial markers. SckryscrapAR allows to see each iterative version of the code, showing its evolution. Each building represents a class, while each city lot represents package. Area of the building represents the current line of a code of the selected version, while the green base the highest line of code in the class life. The height of the building encodes the code churn, i.e. how much the class have changed through its lifetime. Last, red building shows class that have change from the previous version.
The advantage of using fiducial marker is that navigation is straightforward, simply move the maker and the visualization will follow. For more complex interaction, like selection, a mouse is used to click on the building. Then a keyboard input allows to show/hide all building not changed and not selected.