FastJet was written and is developed/maintained by 

Matteo Cacciari
Gavin P. Salam
Gregory Soyez

see http://fastjet.fr/

It provides longitudinally invariant Kt, and inclusive
Cambridge/Aachen and anti-kt (etc.) clustering using fast geometric
algorithms, with area measures and optional external jet-finder
plugins. Please cite hep-ph/0512210 if you use this code. 

This package uses T.Chan's closest pair algorithm, Proc.13th ACM-SIAM
Symp. Discr. Alg, p.472 (2002), S.Fortune's Voronoi algorithm and code
and CGAL: http://www.cgal.org/
