Mostly 1835
askwaltstollmd.com
Contains information on 1835 (Germany), including a FAQ and rules for variants. Maintained by Bill Stoll. The page also hosts 1835 pbem games.
18xx Rules Difference List
fwtwr.com
Includes an analytical list of rule differences among 18xx games. It covers most games and is maintained by Nick Wedd.
Westpark Gamers
westpark-gamers.de
Links and information about the series.
Mark Derrick
home.chattanooga.net
Includes information concerning Mark Derrick's 18xx designs: 18TN (Tennessee, also known as 1851), 18GA (Georgia) and 18AL (Alabama).
1870 Play-by-eMail
pw2.netcom.com
Site for pbem games of 1870 (Mississippi Valley). Includes FAQ, rules clarification, reviews and strategy guidelines. Maintained by Nick Markevich.
Blackwater Station
18xx.net
Information on amateur, gamekits, and commercially available games. Features reviews, news, beginner's guide, and overview of existing games.
Rails18xx
rails18xx.it
Marco Rocci's Rails18xx software suite. Includes information and downloads for TileDesigner, GameSetDesigner and GameModerator applications.
Crisis
home.snafu.de
By Robert Jasiek. An urban game design. Features general and historical information.
The Depots Platform
geocities.com
A Website Devoted to the 18XX Game System.
Ps18xx
swt.cs.tu-berlin.de
Contains downloadable PostScript files of maps and tiles for most 18xx games. Postcard ware by Matthias Klose.
Minstrel HT
pages.eidosnet.co.uk
18xx games - supplement to the paper based Minstrel and links into the UK postal gaming hobby
Lonny's 18xx
8ung.at
Leonhard Orgler's 18xx designs: 1837 (Austria) and 1854 (Austria).
Information about 18xx + 18xx/PC Moderator
18xx.de
This german site is the homepage of the 18xx moderator program. It contains information about 18xx variants and other free software.