Due to the negative impact of code cloning on software maintenance efforts as well as on program correctness [4–6], the duplication of code is generally viewed as problematic. However, the techniques and tools developed by the research community in the last decade have not found broad acceptance in software engineering practice yet. This tutorial contributes to a more widespread application of existing approaches by illustrating where cloning comes from, what its consequences are, and how it can be detected. Categories and Subject Descriptors D.2.9 [Software Engineering]: Management—SQA Keywords Redundancy, Clone Detection