PHYLIP (PHYLogeny Inference Package) is a free computational phylogenetics package of programs for inferring evolutionary trees (phylogenies). It consists of 35 portable programs, i.e. the source code is written in C and precompiled executables are available for Windows (95/98/NT/2000/me/XP), Mac OS 8 and 9, Mac OS X, and Linux systems. Complete documentation is written for all the programs in the package and is part of the package. The author of this package is Joseph Felsenstein, Professor in the Department of Genome Sciences and the Department of Biology at the University of Washington, Seattle.