We present Galileo, a dynamic fault tree modeling and analysis tool that combines the innovative DIF-Tree analysis methodology with a rich user interface built using package-oriented programming. DIFTree integrates binary decision diagram and Markov methods under the common notation of dynamic fault trees, allowing the user to exploit the benefits of both techniques while avoiding the need to learn additional notations and methodologies. Package-oriented programming (POP) is a software architectural style in which large-scale software packages are used as components, exploiting their rich functionality and familiarity to users. Galileo can be obtained for free under license for evaluation, and can be downloaded from the World-Wide Web.