This document is a dissertation presented by Samuel Coleman to the faculty of the Shirley M. Hufstedler School of Education at Alliant International University in partial fulfillment of the requirements for a Doctor of Education degree. The dissertation examines factors that contribute to a teacher's decision to use free and open-source software in the classroom. It provides a literature review on change theory, diffusion of innovation theory, and the adoption process as they relate to a teacher's choice to use FOSS or proprietary software. The study uses a quasi-experimental research design and independent t-tests to analyze differences between teachers who use FOSS, proprietary software, and no software.