Hans Mielants' Simulation Website
Simulation is the most intensive and extensive tool to understand system behaviour.  It is used in research, training & development and leisure time.
Links
General
Very complete site on wargaming.
Companies
Gene, Mike and Terry deliver excellent wargames.  Especially the GBoH series.
GMT
Click here for my ASL page
Games
Frequently referred to as THE GAME, ASL allows you to explore any tactical situation in World War 2.
MMP
The guys who took over ASL and The Gamers.
Grognard
Consimworld
Forum on conflict simulations.
Clubs
Currently playing
The Old Lady.  The game that got me into real wargaming in 1983.
Active club from Ghent, Belgium.
Computer wargaming.
Baltic Gap has is available!
iSimulacrum
Others
Wargame database, aka Simbase
PanzerBlitz II : Hill of Death is out.
Gaming site with discussion forum
News
Baltic Gap is a game on the Soviet assault on the Baltic states in the Summer and Autumn of 1944. It is part of the OCS series of MMP.
Importance of Simulation as a Mode of Analysis.  Article in the BTNG, Belgian Academic Journal for Contemporary History
Research
EvE Online. Society in the 234th Century. A Massive Multiplayer Online game