This article presents a proposal for the detection of programming source code similitude in academic environments. The objective of this proposal is to provide support to professors in detecting plagiarism in student homework assignments in introductory computer programming courses. The developed tool, CODESIGHT, is based on a modification of the Greedy String Tiling algorithm. The tool was tested in one theoretical and three real scenarios, obtaining similitude detections for assignments ranging from those that contained code without modifications to assignments containing insertions of procedural instructions inside the main code. The results verified the efficiency of the tool at the first five levels of the plagiarism spectrum for programming code, in addition to supporting suspicions of plagiarism in real scenarios. © 2013 Wiley Periodicals, Inc. Comput Appl Eng Educ 23:13–22, 2015; View this article online at http://wileyonlinelibrary.com/journal/cae; DOI