Tom is a pattern matching compiler, developed at Universite de Lorraine and Inria. It is particularly well-suited for programming various transformations on trees/terms.
The documentation is available here
The Tom compiler is licensed under the GNU General Public License (GNU GPL, available at http://www.gnu.org/licenses/).
The predefined mappings ($TOM_HOME/share/tom), the runtime library, and the examples are licensed under the BSD License (available at http://www.opensource.org/licenses/bsd-license.php).
Thanks for using Tom.
The Tom Project