This is a unique, technically sophisticated package for geometry which can be used to learn Euclidean, projective, spherical, and hyperbolic geometry; conduct exacting geometric research on automated theorem proving; and serve as an authoring tool for designing web pages with interactive geometric constructions. It is distinguished from its competition by the use of the most elegant algorithms as well as its Java based code that allows it to run on Windows, Unix, Linux, or Mac. Cinderellas visualization capabilities also allow users to view and manipulate geometric constructions in different planes simultaneously.