GAP - Groups, Algorithms and Programming
Gap was created at Lehrstuhl D für Mathematik (LDFM), RWTH Aachen, Germany, and continuing development and maintenance of GAP is coordinated by the School of Mathematical and Computational Sciences at the University of St. Andrews, Scotland.
Type gap to run the program.
DPMMS users with experience of or interest in GAP include Stuart Martin, Jan Saxl, Arthur Gibson and Simon Norton.