This paper introduces RHYTHMOS: an interactive software system designed as a tool-kit for the visualization, exploration, understanding, analysis, praxis, and composition of musical notated (symbolic) rhythms. As such it provides user-friendly bridges between art (music composition), performance (praxis), mathematics (cyclic polygons and the distance geometry of point sets on a circle), and science (the psychology of music perception). A description is provided of the systems capability and interactive graphical user interface. Applications to teaching, learning, and practicing rhythms are discussed. Examples are given of the kinds of research that RHYTHMOS facilitates. These include the testing of rhythmic features for the classification, clustering, and phylogenetic analyses of families of rhythms.