GNU Parted is free software, covered by the GNU General Public License Version 2. This should have been included with the Parted distribution, in the COPYING file. If not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
Libparted is considered part of GNU Parted. It is covered by the GNU General Public License. It is NOT released under the GNU Lesser General Public License (LGPL).