treePL (/ˈtriːpəl/) is a phylogenetic penalized likelihood program.

More information on installation can be found on the wiki https://github.com/blackrim/treePL/wiki

Constraint checking (R) code, along with example data, is available here: https://github.com/blackrim/treePL/tree/master/constraint_checker