Gnudialer is a Open Source predictive dialer licensed under GNU GPL. Currently development for Gnudialer has been ongoing for almost two years.

The Puff series is a low resource predictive dialer that uses the Asterisk PBX. It can manage 30+ agents using less than $800.00 in computer hardware (not including telephony hardware if the application requires it).

Gnudialer is very customizable. It's a multi-process object oriented application written in C++.