Ton Hospel, <Graph-Layout-Aesthetic@ton.iguana.be> for the perl code and the xs wrappers.
Much of the C code is equal to or derived from the original code by D. Stott Parker.
Much of the C code is copyrighted by D. Stott Parker, who released it under the GNU GENERAL PUBLIC LICENSE (version 1).
Copyright (C) 2004 by Ton Hospel for the perl code and the xs wrappers. To be compatible with the original license these pieces are also under the GNU GENERAL PUBLIC LICENSE.