  ESPSim is an open source JAVA program that enables the comparisons of protein
electrostatic potential maps via the computation of an electrostatic similarity
measure. This program has been utilized to demonstrate a high degree of
electrostatic similarity among the potential maps of lysozyme proteins,
suggesting that protein electrostatic states are conserved within lysozyme
proteins. ESPSim is freely available under the AGPL License from
http://www.bioinformatics.org/project/?group_id=830
