Improved tool support for the investigation of duplication in software

Code duplication is a well documented problem in software systems. There has been considerable research into techniques for detecting duplication in software, and there are several effective tools to perform this task. However, a common problem with such tools is that the result set returned can be too large to handle without complementary tool support. The goal of this paper is to describe the criteria for a complete tool that is designed to aid in the comprehension of cloning within a software system. Furthermore, we present a prototype of such a tool and demonstrate the value of its features through a case study on the Apache httpd Web server. For example, in our study we found that a single subsystem comprising only 17% of the system code contained 38.8% of the clones.