fastDNAml is a program derived from Joseph Felsenstein's version 3.3 DNAML (part of his PHYLIP package). Users should consult the documentation for DNAML before using this program. fastDNAml is an attempt to solve the same problem as DNAML, but to do so faster and using less memory, so that larger trees and/or more bootstrap replicates become tractable. Much of fastDNAml is merely a recoding of the PHYLIP 3.3 DNAML program from PASCAL to C.