All the people reporting problems and fixes.  More specifically in
alphabetical order:

Alban Crequy
 For discovering that expected Perl exit code could be unintentionally
 overridden in forks END block and providing a patch suggestion.

Elizabeth Mattijsen
 For providing me (Eric Rybski) the opportunity to maintain and 
 improve this great module.

Erwan Velu
 For finding that system() might not return correct exit value on
 certain target platforms.
 
Nilson Santos Figueiredo Junior <nilsonsfj@cpan.org>
 For helping identify a problem with locks and large PIDs, and
 for helping test and refine general BSD kernel compatibility.

Richard Faasen
 For discovering that some XS code was incompatible with older
 gcc versions.


ORIGINAL AUTHOR CREDITS

Stephen Adkins
 For finding that a child thread could not wake the very first parent
 thread with cond_signal, and providing a patch to fix it.

Arthur Bergman
 For implementing the first working version of Perl threads support
 and providing us with an API to build on.
 
 For Hook::Scope (from which I swiped the code to have locked variables
 automatically unlock upon leaving the scope they were locked in) and
 threads::shared (from which I swiped the code to create references from the
 parameter list passed to a subroutine).

Lars Fenneberg
 For helping me through the initial birthing pains.

Paul Golds
 For spotting a problem with very large shared scalar values.

Bradley W. Langhorst
 For making sure everything runs with warnings enabled.

Juerd Waalboer
 For pointing me to the source filter solution for Perl 5.6.x.