e than previously established, appearing at various levels of abstraction, in diverse systems and languages. The implications of this phenomenon cover various aspects of software engineering research and practice. Categories and Subject Descriptors: D.2.5 [Software Engineering]: Testing and Debugging; D.2.8 [Software Engineering]: Metrics--Product metrics; D.2.9 [Software Engineering]: Management--Software quality assurance (SQA); D.2.13 [Software Engineering]: Reusable Software-Reusable libraries; reuse models; G.3 [Probability and Statistics]: General Terms: Measurement, Languages Additional Key Words and Phrases: Scale-free networks, power laws ACM Reference Format: Louridas, P., Spinellis, D., and Vlachos, V. 2008. Power laws in software. ACM Trans. Softw. Engin. Method. 18, 1, Article 2 (September 2008), 26 pages. DOI = 10.1145/1391984.1391986 http://doi.acm.org/10.1145/1391984.1391986