Visualizing and Navigating Source Code History

We present the Source Code History Navigator, a tool for visualizing the evolution of source code and comparing many revisions of a source code file. Our tool provides an overview of the entire history of a source file through a “history flow”-style visualization in which revisions are plotted as vertical pixel stripes, with each pixel line in a stripe corresponding to a line in the revision and coloured according to some property of interest (e.g., authorship of the line, differences from previous and next revisions, line type, or code age.) Stripes can be expanded to obtain a detail view showing the entire text of the revision. Many such text viewers can be opened side-by-side simultaneously, and their scrollbars can be locked together, facilitating easy comparison of differences across multiple revisions. We present a detailed usage scenario to demonstrate the applicability of our tool.