Free/Open Source Software (FOSS) applications meet many of the software needs of high school science classrooms. In spite of the availability and quality of FOSS tools, they remain unknown to many teachers and utilized by fewer still. In a world where most software has restrictions on copying and use, FOSS is an anomaly, free to use and to redistribute without restrictions. Using FOSS instead of the ubiquitous proprietary applications most commonly used can seem as heretical and as impossible as did Copernicus's suggestion that the Earth was not the center of the universe. This paper suggests one of the factors that keeps schools from adopting--or even considering--FOSS is that its very existence can be written off as an anomaly. Additionally, it shows similarities between the development of FOSS and the development of scientific knowledge. Moreover, it provides examples of FOSS for high school science classrooms.