The Strat Add and Stratigraphic Tools packages for Mesquite, by Michel Laurin and colleagues, can be obtained by starting Mesquite version 3.2 or later, selecting "Check Now for Notices/Installs" from the File menu, and entering the following URL:
http://mesquiteproject.org/packages/stratigraphicTools/install.xmlSource code may be obtained from http://github.com/MesquiteProject/StratigraphicTools