Source Code Revision History Visualization Tools: Do They Work and What Would it Take to Put Them to Work?

Source code revision history visualization tools have been around for over two decades. Yet, they have not become a mainstream tool in a typical programmer's toolbox and are not typically available in intergraded development environments. So, do they really work? And if they do, what would it take to put them to work? This paper seeks to answer these two questions through experiments, surveys, and interviews. A source code history visualization tool named TeamWATCH was implemented to visualize subversion code repositories. Two comparative controlled experiments were conducted to evaluate the effectiveness of TeamWATCH. The experimental results showed that the subjects using TeamWATCH spent less time than subjects using the command-line subversion client and TortoiseSVN in answering the same set of questions regarding source code revision history. In addition, surveys and interviews were conducted to identify obstacles in adopting source code history visualization tools. Collectively, the results show that source code history visualization tools do bring value to programmers. Key obstacles to wider adoption in practice include nontrivial overhead in using the tools and perceived complexity in visualization.