Andy Watkins offers a set of free wargames rules called Brigade Commander, for games set in Cold War Germany. Given the equipment used, I suppose it also would be useful for gaming some other scenarios in which the combatants have old NATO and Warsaw Pace equipment.
I’ve painted a lot of 15mm and microarmor miniature wargaming vehicles in the last few years. Finding photos to help me in assembly and painting has always been a pain. This site is the cure. It has links to several dozen sites that detail WWII through modern military vehicles.
A Spanish Crossfire is a set of modifications for playing Crossfire game set in the Spanish Civil War, and in the Rif War.
Tripoli Blood and Sand is a set of fast-play wargames rules for The Italian-Turkish War, 1911-1912, and Sanusiyya Revolt, 1912-1931, in 6, 15, 20, 25 and 28mm.
Battle For 2mm Earth is a set of free wargames rules for pre WWI wargames in 2mm scale.