KtJet: A C++ implementation of the Kt clustering algorithm
  A C++ implementation of the Kt jet algorithm for high energy particle collisions is presented. The time performance of this implementation is comparable to the widely used Fortran implementation. Identical algorithmic functionality is provided, with a clean and intuitive user interface and additional recombination schemes. A short description of the algorithm and examples of its use are given. 
J. M. Butterworth, J. P. Couchman, B. E. Cox and B. M. Waugh