Atlas Games (free Penumbria stuff) Free samples from Atlas Games Penumbria range (including new clerical domain of time) http://www.atlas-games.com/penumbra/pendloads.html
DaemonEye Publishing (Prometheus) Dead Stars, Molokai, The Can Of... range, Complete Psionics Rules (This publisher is converting from d20 to Prometheus so some products are on hold) http://www.geocities.com/strutinan/index.html
Mongoose Publishing (free stuff) Tons of great free stuff! I had to hit the page down button 17 times just to see it so there are far too many goodies to describe!! http://www.mongoosepublishing.com/freematerial.php
The Wanderers Guild An "in character" organisation that funds and organises expeditions to expand knowledge (Supplements are published in association with Goodman Games) http://www.wanderersguild.com/home.htm
Vintyri Project A project to develop a gameworld called Vintyri world. Their page contains a free setting design guide and the gameworld itself will be offered free once it is finished. http://www.vintyri.com/vintyri/index.htm