kpm is heavily based on Mattias Engdegård's qps. The main difference between kpm and qps is the KDE interface. kpm adheres to most KDE standard, uses the KDE config files and has session managment. Some features of qps were removed (i.e. the ability to display Mac OS7 style tables or special checkbox widgets).
qps (and thus kpm) is published under the GNU General Public License (GNU GPL).