I'd like to keep specific discussions out of this list topic. But I'll try to link this post to discussions in other topics, so that people can find lots of information about Undermountain by hopping over.
LIST OF UNDERMOUNTAIN RPG PRODUCTS:
- The Ruins of Undermountain - Published 1991 for 2nd Edition
- The Ruins of Undermountain II: The Deep Levels - Published 1994 for 2nd Edition
- Undermountain: The Lost Level - Published 1996 for 2nd Edition
- Undermountain: Maddgoth's Castle - Published 1996 for 2nd Edition
- Undermountain: Stardock - Published 1996 for 2nd Edition
- Skullport - Published 1999 for 2nd Edition
- Expedition to Undermountain - Published 2007 for 3.5 Edition
- Undermountain: Halaster's Lost Apprentice - Published 2010 for 4th Edition (D&D Encounters)
- Halls of Undermountain - Published 2012 for 4th Edition
- Forgotten Realms Campaign Setting - Published 2001 for 3rd Edition - Pages 179, 180, 181, 269, 283, 294 and 295
- Descent to Undermountain - Published 1997 by Interplay
- Neverwinter Nigts: Hordes of the Underdark - Expansion pack to Neverwinter Nights published 2003 by BioWare - Has a section of the game set in Undermountain
- The Nobles: Book Three: Escape from Undermountain - Published 1996
- Dragon Magazine 167: Game Wizards: Understanding Undermountain - The King of All Dungeons - Published 1991 - Design notes by Ed Greenwood
- Dragon Magazine 227: Report from Undermountain - Published 1996 - Article giving in-character news of changes in Undermountain by Steven E. Schend