
Julian Seward was the original founder, designer and author, created the
dynamic translation framework, wrote Memcheck and Addrcheck, and did
lots of other things.

Nicholas Nethercote did the core/tool generalisation, wrote
Cachegrind and Massif, and tons of other stuff.

Jeremy Fitzhardinge wrote Helgrind and totally overhauled low-level
syscall/signal and address space layout stuff, among many other things.

Tom Hughes did a vast number of bug fixes, and helped out with support
for more recent Linux/glibc versions.

Robert Walsh added file descriptor leakage checking, new library
interception machinery, support for client allocation pools, and minor
other tweakage.

Dirk Mueller contributed the malloc-free mismatch checking stuff
and other bits and pieces, and acted as our KDE liaison.

Cerion Armour-Brown helped with porting efforts to PowerPC.

Frederic Gobry helped with autoconf and automake.

Daniel Berlin modified readelf's dwarf2 source line reader, written by Nick
Clifton, for use in Valgrind.

Michael Matz and Simon Hausmann modified the GNU binutils
demangler(s) for use in Valgrind.

And lots and lots of other people sent bug reports, patches, and very 
helpful feedback.  Thank you all.