Nathan Carter earned his PhD in mathematics at Indiana University in July 2004. He received the University of Scranton Excellence in Mathematics Award in 1999, an Indiana University Rothrock Teaching Award in 2003, and a Bentley College Innovation in Teaching Award in 2007. Visual Group Theory is his first book, based on lessons learned while writing the software Group Explorer. Like several of his research projects, it puts computers to work to improve mathematical understanding and education.