Developer: Bohemia Interactive
Price: free (JCOVE Lite)
VBS2 is Arma 2's serious stepbrother. If you have the good fortune to reside in the UK, it's also the best free soldier sim around. Thanks to the generosity of the MoD, any Brit can download a gratis copy. Though JCOVE Lite includes few missions, an Arma-style editor and an ample unit selection means the potential for DIY fun is almost limitless.
Past and present military users: Australia, Canada, Finland, Israel, The Netherlands, New Zealand, United Kingdom, United States.
Price: £9 (CMSF)
Long before CM: Shock Force's grim Syria prediction came semi-true, the game was testing the tactical fitness of infantry COs at CGSC. CMSF's WWII predecessor, Afrika Korps, has also done a stint in the schoolroom. A version was made for the Australian Defence Dept. in 2004.
Past and present military users: Australia, United States.
Point of Attack 2
Developer: Scott Hamilton
Reading PoA2's user roster is like perusing a list of RazorWire Inc's best clients. US military HQs, weapon schools, training centres, research stations... somewhere in the States right now a DoD drone is using this alarmingly well-appointed battle sim to figure out how best to respond to a Giant Spider attack on DC.
Past and present military users: United States.
Developer: Eagle Dynamics
When the USAF spruced-up their ageing Warthogs, they got flight sim vets Eagle Dynamics to build a DTS (Desk Top Simulator) to help fliers adapt. Later it was used as the core of a UAV pilot sim and the avionically awesome DCS: A-10C.
Past and present military users: United States
Steel Beast Pro
Developer: eSim Games
Steel Beasts Pro is to World of Tanks what a wedge of vintage Stilton is to a Dairylea Triangle. The price might be relatively high and the engine a tad dowdy (a new one is in the works) but if you're after authentic angry house aggro, it's an essential purchase. Planned for the next payware update are dynamic non-combatants and several new steeds.
Past and present military users: Australia, Austria, Chile, Finland, New Zealand, The Netherlands, Norway, Sweden.