For reference, the old Atlas Games Delphi forum's read-only archive can be found at atlas-games.com/forumARCHIVE/index.html. Many basic questions about our OGL RPGs may already be answered there.
These links may also be of interest:
Official Penumbra Webpage - atlas-games.com/penumbra/index.php
Official Coriolis Webpage - atlas-games.com/coriolis/index.php
Penumbra & Coriolis Errata - atlas-games.com/penumbra/penerrata.php
Official Northern Crown Webpage - atlas-games.com/crown/index.php
Northern Crown Errata - atlas-games.com/crown/NCerrata.php
Official Nyambe Webpage - atlas-games.com/nyambe/index.php
Nyambe Errata - atlas-games.com/nyambe/nyambefaq.php