Below is a (hopefully complete) list of people who have contributed to stellarcollapse.org.
Ernazar Abdikamalov (Nazarbayev University)
Chris Belczynski (Warsaw)
Drew Clausen (Caltech)
Sean Couch (MSU)
Bill Engels (industry/Caltech)
Davide Gerosa (Cambridge)
Sarah Gossan (Caltech)
Roland Haas (AEI)
Matthias Hempel (Basel)
Jeff Kaplan (industry)
Peter Kalmus (JPL)
James M. Lattimer (Stony Brook)
Jonas Lippuner (Caltech)
Viktoriya Morozova (Caltech)
Philipp Mösta (UC Berkeley)
Jeremiah W. Murphy (Florida State)
Evan O'Connor (NC State)
David Radice (Caltech)
Christian Reisswig (industry)
Mathieu Renzo (Amsterdam)
Sherwood Richers (Caltech)
Luke Roberts (Caltech)
Ulrich Sperhake (Cambridge)
Andrew W. Steiner (UTK)
Fang Peng (industry)
Tony Piro (Carnegie)
Grzegorz Wiktorowicz (Warsaw)