http://www.outrage.com/
The guys who made it happen!

http://www.graphsim.com/games/games-action.html
D3 for the Mac.

http://www.lokigames.com/products/descent3/
D3 for Linux.

http://www.volition-inc.com/
The other half ;) Working on cool games like Freespace, Red Faction and Summoner.

http://www.kali.net
Join server -> Descent <- to meet tons of hardcore Descenters.

http://www.myrkul.org/descent.html
Tips on how to reduce lag; originally done for D1/D2 but a lot of info also applies to D3.

http://d3shiva.dhs.org
Shiva's SOD site with the servers, etc. and Linux support.

http://www.wildcards.org/zappafan/
1000+ cool reviews & download of custom-made Descent levels

http://www.warpcore.org/~d3sdk/
The source for MOD-developers

http://www.descentforum.de/forum/
THE place to talk about everything Descent in German

http://feedback.interplay.com/descent3/
Unmoderated fan talk; archive only, no new postings.

alt.games.descent
Usenet

#300baud, #descent on EFFNET
IRC

http://descent2.com/hoppe/
Descent Dogfight Tactics

http://moon.descent-3.com
Walkthroughs, Map-Screenshots & How-To-Demos on Descent 1-3

http://www.descent3d.com/articles/tetrad-entropy.shtml
Tetrad's Entropy Guide

http://www.planetdescent.com/site/files/d3/mods/index.asp http://www.levels4you.com/d3/index.php3?page=mod
These sites have a slew of MODS