Here is a list of developers who have committed to the PyPy source code base, ordered by number of commits (which is certainly not a very appropriate measure but it’s something):
Armin Rigo
Maciej Fijalkowski
Carl Friedrich Bolz
Antonio Cuni
Amaury Forgeot d'Arc
Samuele Pedroni
Michael Hudson
Holger Krekel
Benjamin Peterson
Christian Tismer
Hakan Ardo
Alex Gaynor
Eric van Riet Paap
Anders Chrigstrom
David Schneider
Richard Emslie
Dan Villiom Podlaski Christiansen
Alexander Schremmer
Aurelien Campeas
Anders Lehmann
Camillo Bruni
Niklaus Haldimann
Leonardo Santagada
Toon Verwaest
Seo Sanghyeon
Lawrence Oluyede
Bartosz Skowron
Jakub Gustak
Guido Wesdorp
Daniel Roberts
Adrien Di Mascio
Laura Creighton
Ludovic Aubry
Niko Matsakis
Jason Creighton
Jacob Hallen
Alex Martelli
Anders Hammarquist
Jan de Mooij
Wim Lavrijsen
Stephan Diehl
Michael Foord
Stefan Schwarzer
Tomek Meka
Patrick Maupin
Bob Ippolito
Bruno Gola
Alexandre Fayolle
Marius Gedminas
Simon Burton
Justin Peel
Jean-Paul Calderone
John Witulski
Lukas Diekmann
holger krekel
Wim Lavrijsen
Dario Bertini
Andreas Stührk
Jean-Philippe St. Pierre
Guido van Rossum
Pavel Vinogradov
Valentino Volonghi
Paul deGrandis
Adrian Kuhn
tav
Georg Brandl
Gerald Klix
Wanja Saatkamp
Ronny Pfannschmidt
Boris Feigin
Oscar Nierstrasz
David Malcolm
Eugene Oden
Henry Mason
Sven Hager
Lukas Renggli
Ilya Osadchiy
Guenter Jantzen
Bert Freudenberg
Amit Regmi
Ben Young
Nicolas Chauvat
Andrew Durdin
Michael Schneider
Nicholas Riley
Rocco Moretti
Gintautas Miliauskas
Michael Twomey
Igor Trindade Oliveira
Lucian Branescu Mihaila
Olivier Dormond
Jared Grubb
Karl Bartel
Gabriel Lavoie
Victor Stinner
Brian Dorsey
Stuart Williams
Toby Watson
Antoine Pitrou
Justas Sadzevicius
Neil Shepperd
Mikael Schönenberg
Gasper Zejn
Jonathan David Riehl
Elmo Mäntynen
Anders Qvist
Beatrice During
Alexander Sedov
Timo Paulssen
Corbin Simpson
Vincent Legoll
Romain Guillebert
Alan McIntyre
Alex Perry
Jens-Uwe Mager
Simon Cross
Dan Stromberg
Guillebert Romain
Carl Meyer
Pieter Zieschang
Alejandro J. Cura
Sylvain Thenault
Christoph Gerum
Travis Francis Athougies
Henrik Vendelbo
Lutz Paelike
Jacob Oscarson
Martin Blais
Lucio Torre
Lene Wagner
Miguel de Val Borro
Ignas Mikalajunas
Artur Lisiecki
Philip Jenvey
Joshua Gilbert
Godefroid Chappelle
Yusei Tahara
Christopher Armstrong
Stephan Busemann
Gustavo Niemeyer
William Leslie
Akira Li
Kristjan Valur Jonsson
Bobby Impollonia
Michael Hudson-Doyle
Andrew Thompson
Anders Sigfridsson
Floris Bruynooghe
Jacek Generowicz
Dan Colish
Zooko Wilcox-O Hearn
Dan Villiom Podlaski Christiansen
Anders Hammarquist
Chris Lambacher
Dinu Gherman
Dan Colish
Brett Cannon
Daniel Neuhäuser
Michael Chermside
Konrad Delong
Anna Ravencroft
Greg Price
Armin Ronacher
Christian Muirhead
Jim Baker
Rodrigo Araújo
Romain Guillebert