GeoGebra is a community-supported open-source mathematics learning environment that integrates multiple dynamic representations, various domains of mathematics, and a rich variety of computational utilities for modeling and simulations. Mathematics teachers describe how it can be used in teaching model-centered mathematics. Among their topics are how it can inspire technology integration in mathematics, from simulation to formalization in teacher preparation and in-service programs, visualization through dynamic GeoGebra illustrations, where cognitive theories and technology meet, approaches to calculus, and its emerging role in the Philippines. There is no index. Annotation ©2012 Book News, Inc., Portland, OR (booknews.com)