Find out how to get sources from PAL.
If you look for actual integrations, go to the list of projects which use PAL labeling library.
svn co http://geosysin.iict.ch/pal-svn/trunk pal-dev
PAL labeling library is released under GNU Lesser General Public License (LGPL) licence by School of Business and Engineering Vaud (University Of Applied Sciences Western Switzerland). Moreover, it is maintained and developped within an opensource community.