you can play most of the old games for free live or pbem through Vassal or ( http://www.vassalengine.org ) Cyberboard (PBEM only) there are few online as regular wargames - abandondware version of AH Rise and Decline of the Third Reich (AI is pretty poor) can be found on theunderdogs. Hitler's War, (no AI) is good and there's a great fan version of Wizards Quest with a good AI for the orcs. I'm sure there are more.