Main author: Denis Auroux (auroux@math.mit.edu, auroux@math.berkeley.edu) The source code includes contributions by the following people: Eduardo de Barros Lima, Mathieu Bouchard, Ole Joergen Broenner, Vincenzo Ciancia, Luca de Cicco, Michele Codutti, Robert Gerlach, Lukasz Kaiser, Danny Kukawka, Stefan Lembach, Bob McElrath, Andy Neitzke, David Planella, Marco Poletti, Alex Ray, Jean-Baptiste Rouquier, Mike Ter Louw, Uwe Winter, Lu Zhihe. (Let me know if you are missing from this list or if your name is mis-spelled)