treePL (/ˈtriːpəl/) is a phylogenetic penalized likelihood program. More information on installation can be found on the wiki https://github.com/blackrim/treePL/wiki A Mac 10.9 binary package can be found as treePL_mac10_9_binary.tgz in the repository (contributed by Joseph Brown). It may be necessary to change the permissions to make this executable. Type: chmod 755 treePL