NWN Official
BioWare: NWN Developer main site
Neverwinter Nights: BioWare's official game title info site
BioWare: Neverwinter Nights: BioWare's NWN subsite with the real info
BioWare NWN Forums: Official NWN message boards
NWN Official Community: BioWare's upcoming official Community site and portal to Official Vault Modules
Betatests.Net: NWN Beta Test Signup (buggy, use IE 5.5 or above)
Infogrames: NWN Publisher corporate site
Infogrames NWN Order Site
 
NWN Megasites
Neverwinter Vault: Part of the ign.com network
Neverwinter Nights Stratics
Planet Neverwinter
Neverwinter Sage
Neverwinter Nuts
Neverwinter Nights WebRing
Neverwinter Haven
NWN Module, World, Guild and Group Tracking
NWN Official Community: BioWare's upcoming official Community site and portal to Official Vault Modules
Neverwinter Nexus: A great one stop site for everything NWN
NwConnections.Com
NZNights: Australia and New Zealand timezone friendly.
The RPG Consortium NetPortals - NWN
End of Infinity: Links and Module Database and Resource site
 
NWN Scripting
NWVault Scripting University: Step by step tutorials in C basics and some specific NWNScript
Neverwinter Nights Scripting Forum (NWVault): Discussion of actual NWNScript
NWScript Reference Guide: Fan updated reference taken from official content
AuroraScript (NWNScript) PDF Reference Sheets: Fan updated reference in PDF file format
InfinityScripters: Scripting group from BG/BGII/etc fame gearing for NWN *(Mprilla)
 
NWN Persistent Worlds
The Fall of Aridor: *(Surgeon_General)
Area32: *(Ondaderthad)
Shroud World: *(Segal)
The World of Sidria: *(Methcalcior)
Crystallania: *(Devious)
Errant Lands: *(Cyrana)
Vagabondia Online: *(Gladimir)
 
NWN Campaign Module Projects
The Land of Caern: *(Gurney999)
 
NWN Groups of Specific Focus
Ladies of Neverwinter
The Pantheon of Godz: "We were known as a Haven for true players of RPG." *(Athena)
 
NWN Custom Artwork, Tilesets, and Models
Moradin's Closet
OpenFX: GNU GPL. Open-Source 3D modeling, animation and rendering suite. Really quite impressive, the kind of app you expect to pay large sums of money for.
 
NWN Module Design Tools
NWDialog: Freeware. Based on NWN Toolset, good for encounter conversation flow planning.
NWMap: Freeware. Tile-based mapping utility for indoor and outdoor map creation/editing. Developed with NWN Toolset in mind.

NWNring at the Nexus

AREA32 at the Nexus

Neverwinter Connections (Neverwinter Tavern)

Neverwinterworks

Ondaderthad's maps for HeroesIII (scroll half way down the page to see the pixs)

Other sites

Text-based MU* (MUD, MOO, MUSH, etc) Genre
 
Megasites
The MUD Connector: MU* Listings, reviews, articles, job listings, etc
Kyndig.Com: Mud & Online Text Game Community, articles, reviews, etc
Top MUD Sites: mud list, top muds, mud sites, discussion forums, articles, game reviews
OGR - Online Gaming Resource: MU* resources
Imaginary Realities: MUD Newletter/ezine (slow link)
The MUD Journal
Resources
The MUD Companion: A MUD magizine
KaVir's MUD Site: MUD Resource site by the originator of the GodWars codebase *(KaVir)
MUD Planet A centralized MUD resource site, interviews, editorials, and more.
Game.org: Diku Tree and other code base resource center
 
MU*s of Interest
Thread in the Pattern: Wheel of Time(tm) MUD, under construction *(Sabia)
 
MMOG/MMORPG (UO, EQ, Shadowbane, etc) Genre
 
Ultima Online
UO Official site
Origin Systems Inc.
Electronic Arts
AskChopper.com
UO Powergamers
Markee Dragon
 
Everquest
EQ Official site
Verant Interactive
EQ Vault
EQ Stratics
EQ Atlas
Everlore
 
Asheron's Call
AC Official Site
Turbine Entertainment
AC Vault
 
Anarchy Online
AO Official site
Funcom
AO Vault
 
Dark Age Of Camelot
DAoC Official site
Mythic Entertainment
DAoC Vault
Daughters of Hibernia: DAoC Female Guild *(Aktrez)
 
Shadowbane
SB Official site
SB Vault
 
UO Emulator Info Sites
UO Stratics - Emulator FAQ
Paigelore
Ultima Intelligence Oracle Developement: UO EMU News Site
UOXperience
Ultima Online Central: "The Ultimate Ultima Online Portal Free Resources, Downloads, Links, Emulator Help, Bug Fixes, Scripts, Forums, Complete UO Clients List, etc"
 
UO Emulators
UOX3: UOX3 Development Emulator
UOX3 Sourceforge
UOX Classic: One of the originals
POL: POL Emulator
Sphere: Sphere Server Emulator
UIO: Ultima Inside Out Emulator
LoneWolf: Lone Wolf Emulator
Nox-Wizard: Nox-Wizard Emulator
Hybrid Emulation Systems
Legions of Chaos: UOX3 Based Emulator
 

Graphical-based MUGs (NWN, etc) Genre
 
Games Official
Neverwinter Nights: BioWare's official game title info site
 

 
General World Design and Management Resources
 
General Design Resources
The MUD Development mailing list
Gamasutra
RPG Design Ramblings
Amit's Game Programming Information
The Art of Building: Primarily for MUDS, but good for any world design
 
Artificial Intelligence (AI)
GameAI.com
 
Campaign Resources
Campaign Design Articles
 
RP Resources
RoleplayingTips.com
A Weave Roleplaying Overview: Freeform RP on a WoT themed MUD *(Joffi)
 
Economics
The In-game Economics of Ultima Online: Good paper for any world economy research
 
Graphics, Aninmation and 3D Modeling
OpenFX: GNU GPL. Open-Source 3D modeling, animation and rendering suite. Really quite impressive, the kind of app you expect to pay large sums of money for.
Prowler Art Studio: *(Earp)

Computer Gaming Megasite, News, and Review
 
eZines
Massive Multiplayer.org
Happy Puppy
Gamespot
 
Published Magizines
Computer Gaming World
PC Gamer
 
Gaming Organizations
The Legitimate Players League: *(TubalCain)

Tabletop/Pen and Paper RPG Resources
Good resources for the planning stages of any Module Design also.
 
Megasites and Search Engines
DnDResources.com: Repository listing many apps and tools
EN World/d20reviews Electronic Aids Section: Another repository. Their D&D Software forum is good as well
The Open Gaming Foundation: The d20 standard (and free) rules and documents
Wizards of the Coast
 
Player/DM Matching
RPG Net's Game Directory:  
RPG Registry:  
RPG Player Locator:  
 
Client Server Group Gaming
OpenRPG: An opensource client-server app providing its own chat and game matching, emulating complete PnP RPG group experience through textual (and minor graphics) online means.
Mapster: A suppliment for irc/chat gaming groups to keep their bearings. The DM has a server which shows the map to the players' clients. He controls how much of the map is seen, places and moves figure icons, etc.
 
 
Mapping
AutoREALM: Freeware. "AutoREALM is a freely available fantasy role-playing map making program." I like this one alot for pure mapping potential.
Dungeon Crafter: Freeware. Looks to have possiblities, many like it.
NWMap: Freeware. Tile-based mapping utility for indoor and outdoor map creation/editing. Developed with NWN Toolset in mind.
]ProFantasy: Commercial. Home of Campaign Cartographer and other commercial programs. These were the ones used for the Forgotten Realms Atlas CD release.
NBOS's Fractal Mapper: Commercial. Mapper, large symbol library, and 3D relief map program; Registered versions get access to their online library.'
 
Campaign Tools
RolePlayingMaster: Freeware. "The purpose of RPM is to make the mechanics of your 3rd edition roleplaying much simpler and quicker." Only just begun looking at this package. It has definate possibilities.
Roleplaying Assistant: More of a caimpain designing and DM tool package, for use with numerous d20 rulesets and ability to modify sets to your own taste. Map generators but no map making/editing utility included.  
DM Screen: Freeware. "DM Screen is a program designed for DMs to use as an aid for running their adventures while using a laptop or PC as a Dungeon Master's screen. It features useful tables, dice rollers, a combat planner, a quick NPC name generator, an artifact name generator, and a custom generator. DM Screen has built-in support for your favorite treasure generation program too!"
PC Gen: A very good open source PC/Character Generator.  
Campain Suite - Twin Rose Software: Commercial. Complete d20 caimpain suite. Not expensive, but not free *sigh*
 
Online Tools
iG-Tools: Java applets for everything from map makers to calanders to dice rollers.
Jamis Buck's RPG Generators: Now hosted on ENWorld, city, dungeon, treasure, and NPC cgi generators
 
World Time Reference
World Time Zone: Graphical, applet representation of all timezones.
The World Clock: Text table layout of timezones, current times and dates.