Abstract
Data Mining is one of the most widely used techniques in the realm of data exploration and trend identification. Although commercial Data Mining tools are very powerful and produce satisfactory results, the number of free and open source software tools is on the rise, some of them have started to compete vigorously with the commercial enterprise-level rivals. For small to medium enterprises, selecting a suitable Data Mining tool can be an overwhelming task with such a variety. In this paper, five of the most popular free and open source software tools were comprehensively studied, and compared on a side-by-side manner on both user's acceptance and technical specifications level. Results from both evaluations are analyzed, and the paper concludes by contrasting on the advantages and disadvantages of each tool.