Hello.
We have released the first version of rhythm_estimator, a Pd object for analysing the metrical grid from onset data, using an algorithm as described in http://www.cs.tut.fi/sgn/arg/music/jams/. This implementation of the algorithm is distributed under the GNU General Public License.
You will find the package from: ftp://iem.mhsg.ac.at/pd/Externals/RHYTHM/rhythm_estimator-0.1.tar.gz
-Jarno, Graz