gpkgdep shows the FreeBSD package dependencies in three different views:
- a tree view shows all packages required by each package
- a tree view shows all packages which depend on each package
- a list view allows to play with the packages. By marking 'wanted' packages, all packages depending on them are marked as well. By this obsolete packages can be found easily.
See http://gpkgdep.sourceforge.net/ for details!