At Pumptheory we love software so much we talk about it in our spare time and give it away for free!
Pumptheory is with pumptheory's Mark Aufflick heavily involved in the Australian iOS and Macintosh development community and is the main organiser of CocoaHeads and NSCoder's Sydney chapters where he has also been known to give the occasional presentation. Mark provides various pieces of opensource code to the Cocoa community, such as Net::APNS — a Perl module which manages communication with the Apple Push Notification Service.
Mark is also strongly involved in the global Perl community, developing and maintaining a number of CPAN modules and being a frequent contributor to Perlmonks.org.
In recent times Mark was a significant contributor to the OpenACS web framework community. OpenACS remains one of the richest online community frameworks available, opensource or commercial.
You can see some other opensource and community contributions by Mark on his personal website at http://mark.aufflick.com/software/.