The Operational Art of War is presently on it's fourth incarnation.
The history of the series goes thusly:
1998: The Operational Art of War I: 1939-1955
1999: The Operational Art of War II: Modern Battles 1956-2000
2000: The Operational Art of War: Century of Warfare
(This was the "Gold" compilation of the series, and was more than just "let's put all the scenario packs together!" bundle, it did some bug fixes, allowed more complex scenario trees; and actually extended the database out to about 1914~ and had a few World War I scenarios; so it was essentially 1914-2000.)
2006: The Operational Art of War III
(Matrix brought the rights to TOAW from the last publisher, and updated it to work on modern computers, removed the annoying copy protection, etc; and added new scenarios, bug fixes, additional features, etc, as well as support for custom databases and graphics for each scenario. It contains all the scenarios from Century of Warfare, as well as a ton of new scenarios done for this release.)
TOAW 3 is available from Matrix Games on their website in several forms.
Costs are:
Download
($39.99 USD, $45.99 AUS, $40.99 CAN, £19.99, 27.99 EUR)
Physical Shipment plus Download
($49.99 USD, $56.99 AUS, $50.99 CAN, £24.99, 34.99 EUR)
Digital Download is just that; you get a link to a FTP site to download the installer.
Current file size for the v3.012 installer is 223~ MB; that's about:
8h 36m @ 56k
45m on 640kbps DSL, Satellite or Cable
19m on 1.5mbps DSL or Cable
Physical Shipment is what it says; a boxed DVD case containing the game and a physical CD.
NOTE: Matrix have not updated their installer yet; the current patch is v3.2.29.27; which is a comprehensive update clocking in around at 17 MB.
So you've downloaded the game and patch; and you start to install it.
You see the standard "Oh hi, this is the TOAW 3 installer", the EULA, etc etc; then you come to the copy protection, which is standard across the Matrix Games Line:

Yes; I know the picture is of the Harpoon CE screen. I don't have the TOAW 3 installer handy on my computer right now. But they're the same.
They also ask you for your serial in patches; and update their blacklist of serials which have been "cracked" or released into the wild with each patch. For a niche product like a wargame, this works really well, allowing security for the publisher, and ease of use for the end user.
With the Game + the latest patch you get the following scenarios:
TOAW 1/2 and Century of Warfare scenarios
Balkans 1912 (1st Balkans War)
Balkans 1913 (2nd Balkans War)
France 1914
Serbia-Galicia 1914
Tannenberg 1914
St. Mihiel 1918
Meuse-Argonne 1918
Nomonhan 1939
France 1940
Greece 1940-1941
Crete 1941
Barbarossa 1941
Smolensk 1941
Crusader 1941
Typhoon 1941
Luzon 1941-1942
Singapore 1942
Kharkov 1942
African Campaign 1942
Malta 1942
Tunisia 1942-1943
South Front 1942
Burma 1942-1943
Kasserine 1943
Attu Island 1943
Kursk 1943
Sicily 1943
Kiska Island 1943 [hypothetical] - This assumes the Japanese did not abandon the Island before the invasion.
Italy 1943
Korsun 1944
Overlord 1944
Normandy 1944
Normandy - Rommel 1944 [hypothetical] - What if Rommel had been given total control over dispositions and locations?
Cherbourg 1944
St Lo 1944
Cobra 1944
Mortain 1944
Falaise Pocket 1944
Dragoon 1944
Market Garden 1944
Arracourt 1944
Bulge 1944
Iwo Jima 1945
Patton 1945 [hypothetical] - Soviet offensive against the US Third Army from Czechoslovakia, to seize portions of southern Germany.
Olympic 1945 [hypothetical] - Invasion of Kyushu
Israel 1948
Korea 1950-1951
Chosen 1950
Nghia Lo 1954 - Start of French Indo China War -- Conventional Phase
Dien Bien Phu 1954
Fulda 1955 [hypothetical] - Attack by the newly formed Warsaw Pact against NATO forces to seize Frankfurt.
Middle East 1956 - “Operation Kadesh”, which was a surprise invasion against Egypt in the Sinai Peninsula.
NATO-Warsaw Pact 1962 [hypothetical] - Third World War, triggered by the Cuban Missile Crisis.
Cuba 1962 [hypothetical] - “Operation Scabbards”, a hypothetical invasion of Cuba by the United States in 1962, triggered by the Cuban Missile Crisis.
Ia Drang 1965
Bong Son 1966
Middle East 1967 (Six Day War)
Tet Offensive 1968
Vietnam Invasion 1969 [hypothetical] - “Operation Inchon”, a hypothetical US invasion of North Vietnam.
Sino-Soviet 1969 [hypothetical] - Soviet Union attack against Chinese forces along the Amur River.
Middle East 1973 - Yom Kippur War
Fulda 1976 [hypothetical]
NATO-Warsaw Pact 1978 [hypothetical]
Grenada 1983
Iran-Iraq 1984 - Iranian “Operation Dawn V”, which consisted of human-wave assaults on fortified Iraqi armored units.
Germany 1984 [hypothetical]
Desert Storm 1991
Kuwait 1991
Kashmir 1999 [hypothetical] - Hypothetical war between India and Pakistan over the disputed Kashmir province.
Yugoslavia 1999 [hypothetical] - Invasion of the Federal Republic of Yugoslavia by NATO in June, 1999.
Korea 1999 [hypothetical]
Bulge 2000 [abstract] - This models a massive fictional battle resembling the Battle of the Bulge.
Russo-China 2000 [hypothetical]
Libya-Egypt 2000 [hypothetical]
Hungary-Romania 2000 [hypothetical] - Hypothetical Hungarian war to liberate the Transylvanian region in Romania, taken from Hungary following WWI
Middle East 2000 [hypothetical] - Arab Coalition Attack on Israel
Seoul 2000 [hypothetical] - North Korean sneak attack towards Seoul.
US Civil War 2008 [hypothetical]
Pre-20th Century for TOAW 3 - some were fan made, and have been updated to work with the new game
Waterloo 1815
Killer Angels 1863 - Gettysburg Campaign
This models the Gettysburg Campaign from the American Civil War. This version uses the historical set-up.
Killer Angels 1863 - Jackson Variant [hypothetical] - Jackson is presumed not to have been mortally wounded at Chancellorsville.
Battle of Adua 1896 - This is a tactical-scale simulation of the humiliating Italian defeat at the hands of hordes of Ethiopian primitives
Early 20th Century (WWIish)
Double Eagle/Rising Sun 1904-1905
The Great War 1914-1918
Home Before The Leaves Fall 1914
Tannenberg 1914 (Updated version of classic scenario)
Serbia-Galicia 1914 (Updated version of classic scenario)
Mons 1914
Marne 1914
The Battle on Mount Cer 1914 - This is the decisive battle that foiled the initial Austro-Hungarian offensive against Serbia in the First World War.
Forgotten Battles - Lodz 1914 - This scenario is the first of three covering different parts of the Eastern Front campaign in 1914 - the most mobile part of WWI.
Forgotten Battles - Komarow 1914 - The second scenario of the series simulates the most interesting part of the battle of Galicia - the Battle of Komarow.
Forgotten Battles - Cracow 1914
Gallipoli 1915
Eastern Front 1915
Brusilov 1916
Strafexposition 1916 - Central Powers “Strafexposition” offensive against Italy.
Caporetto 1917 - Central Powers successful “Caporetto” offensive against Italy.
Cambrai 1917
Kaiserschlacht 1918
Kaiserschlacht 1918 (mini) - Quarter-scale copy of the above scenario. So players can pick whichever scale they prefer – the detailed monster or a small “beer and pretzel” version.
Polish-Soviet War 1920
WWII MTO
Italian Offensive In Tunisia 1940 [hypothetical] - Italian invasion of Tunisia in 1940.
Campaign For North Africa 1940-1943 (Complete Campaign) - This scenario is the first of six covering the Campaign for North Africa from different starting points.
Campaign For North Africa 1940D-1943 (O’Connor’s Raid) - Starts with O’Connor’s Raid in December 1940.
Campaign For North Africa 1941-1943 (Rommel’s 1st Offensive) - starts with Rommel’s First Offensive in March 1941.
Campaign For North Africa 1941N-1943 (Crusader) - starts with the Commonwealth Crusader Offensive in November 1941.
Campaign For North Africa 1942-1943 (Gazala) - starts with the Battle of Gazala in May 1942.
Campaign For North Africa 1942O-1943 (El Alamein) - starts with the Second Battle of El Alamein in October 1942.
North African Campaign 1940-1942 -Entire campaign for North Africa from Graziani’s offensive to the end of 1942.
Rommel in North Africa 1941-1942
Italian East Africa 1941
Crete – Operation Merkur 1941
Tobruk 1941
Malta – Operazione C3 1942 [Hypothetical] - Hypothetical Axis invasion of Malta. It includes detailed modeling of the opposing naval forces.
Malta - Operation Hercules 1942 [hypothetical] - (Revised Version of Classic Scenario)
El Alamein 1942 - Minefields are innovatively modeled using “contaminated” terrain.
Operation Torch 1942
Race for Tunis 1942
Last Stand in Africa 1942
Bitter Victory Sicily 1943
Rhodes 1943
Leros 1943
Sicily to Brenner Pass 1943-1945 - monster simulation of the entire Sicily, Italy, and Southern France campaigns.
Italian Campaign 1943-1945
Road to Rimini 1944 - British 8th Army’s part of the Allied “Operation Olive” offensive to breach the Gothic Line in Italy.
Gothic Line 1944 - The Entire Allied “Operation Olive” offensive to breach the Gothic Line in Italy.
WW2 ETO
Vesting Holland 1940
Sealion 1940 [hypothetical]
Operation Roundup 1943 [hypothetical] - Planned “Operation Roundup” invasion of France in 1943.
Two Weeks in Normandy 1944
France 1944 (D-Day)
France 1944 (Cobra)
Western Front 1944-1945
West Wall Campaign 1944 - 1st and 9th US Armies
West Wall Campaign 1944 - 21st British Army Group
Holland – A Bridge Too Far 1944
Ardennes 1944
Rundstedt’s Plan Martin 1944 [hypothetical] - This is the “Battle of the Bulge” with a hypothetically maximized German force mix. All German forces that historically could have been made available are employed in the offensive.
Operation Nordwind 1945 - This simulates the last German offensive on the Western Front.
WW2 Russian Front
Fire in the East 1941-1945 - Monster simulation of the entire War in the East, from the start of “Barbarossa” to the fall of Berlin.
Soviet Union 1941 - Barbarossa at the beer-and-pretzel scale.
Finland 1941
The Road to Moscow 1941 I - Crossing the Border
The Road to Moscow 1941 II - The Battle of Smolensk
The Road to Moscow 1941 III - Guderian moves south
The Road to Moscow 1941 IV – Kiev
The Road to Moscow1941 V - Center-Bryansk and Vyasma
The Road to Moscow1941 VI - At the Gates
The Road to Moscow 1941 VII - Soviet Counteroffensive
The Road to Moscow 1941 VIII – What if… [hypothetical] - German continuation to Moscow after Smolensk, instead of the diversion to Kiev.
Operation Typhoon 1941
Operation Barbarossa 1941
Operation Blau 1942
Operation Zitadelle 1943
Operation Bagration (To Berlin) 1944
2nd Battle of Kharkov 1942
Sevastopol 1942
Wintergewitter 1942
Stalingrad to Kharkov 1942-1943
Frozen Steppes 1942-1943 -Uranus to 3rd Kharkov
Clash of Armor - Kursk 1943
Kursk 1943 (Revised from Classic)
Karelian Isthmus 1944 - Soviet 1944 summer offensive to retake the Karelian Isthmus and knock Finland out of the war.
Petsamo-Kirkenes 1944 - Soviet autumn 1944 offensive in the Arctic.
Hungarian Campaign 1944
WW2 PTO
Sino-Japanese War 1937-1945
Burma Campaign 1942-1945
Guadalcanal 1942
Papua-New Guinea 1942
Imphal-Kohima 1944 - Japanese Invasion of India in 1944.
Inkangahtawng 1944 - “Merrill’s Marauders” in Burma in 1944.
Okinawa 1945
Tarakan 1945 - The costly and needless Australian amphibious invasion of Tarakan.
WW2 Misc
Fall Grun 1938 [hypothetical] - Britain and France call Hitler’s bluff in Czechslovakia.
Europe Aflame 1939-1945
Trotsky’s War 1939-1945 [Hypothetical] - Trotsky takes on the entire west, including Nazi Germany.
Fall Weiss 1939 - German invasion of Poland in 1939.
Poland 1939
Weserubung 1940
Yugoslavia 1941-1945
Germany 1945 – Last Stand - Beer and Pretzel Scale.
Germany 1945 - Race to Berlin - Beer and Pretzel Scale.
NATO vs. Warsaw Pact
The Next War 1979 [hypothetical] - It starts with a “pre-turn” to allow the Warsaw Pact player to choose between “Tension” and “Sudden War”.
Red Thunder 1988 [hypothetical]
Global Conflict 1988 [hypothetical]
Operation Jutland 1989 [hypothetical] - NATO liberation of a Soviet occupied Denmark.
Germany 1990 – North German Plain [hypothetical]
Germany 1990 - British Army of the Rhine [hypothetical]
Germany 1990 – Southern Germany [hypothetical]
Highway to Helsinki 1990 [hypothetical] - Soviet thrust towards the Finnish capital city.
Karelian Pine 1990 [hypothetical] - Soviet offensive in Eastern Finland.
Nordic Light II 1992 [hypothetical] - Russian invasion of Finland and Sweden in the autumn of 1992.
Middle East
Six Days of War 1967
West Bank 1967
Sinai 1967
On the Banks of the Suez 1973
Yom Kippur - Golan Heights 1973
Chinese Farm 1973
Lebanon 1982
The Christmas War 2001 [hypothetical]
Saddam’s Final Gamble 2003 - Monster simulation of Operation Iraqi Freedom.
October Surprise 2004 [hypothetical] - Hypothetical entry of Iran into the Iraq conflict.
Next War in Jerusalem 2005 [hypothetical] - Surprise attack on Israel by Syria, Jordan, Lebanon and Iraq in October 2005.
Israel’s Next War 2006 [hypothetical] Arab/Israeli War
Modern Asia
Indochina 1951-1954
Campaign for South Vietnam 1965-1975
Boonie Rats 1965-1972
Vietnam 1965-1975
Vietnam 1965 Defense Campaign Part 1
Vietnam 1965 Defense Campaign Part 2
Vietnam 1966 Defense Campaign Part 3
Korea 2005 [hypothetical]
Taipei 2015 [hypothetical] - PRC invasion of Taiwan, Part I: Taipei.
Kinmen and Matzu Islands 2015 [hypothetical] - PRC invasion of Taiwan, Part II: Kinmen and Matzu Islands.
Modern Misc.
Walvis Bay 1991 [hypothetical] - A breakdown in the negotiations for Walvis Bay resulted in the Namibian government deciding to take the enclave by force.
First Chechen War 1995-1996
Ecuador 1995 [hypothetical] - Historical/hypothetical hybrid of the conflict between Ecuador and Peru in 1995. Jungle theater operations are historical. It also covers a hypothetical Peruvian offensive along the western coastal border, which nearly occurred.
Zimbabwe 2003 [hypothetical] - invasion of Zimbabwe by South Africa in an attempt to cause the downfall of Mugabe.
Operation Lion de mer 2004 [hypothetical] - conflict between a US/UK coalition and some European Union members.
The Second Battle for France 2004 [hypothetical] -conflict between a US/UK coalition against France and other European Allies.
Aegean 2004 [hypothetical] - crisis in the summer of 2004 in the Aegean. Greece and Turkey go to war over disputes in the Aegean and Cyprus.
Hypothetical Studies
Revisionist War 1937 [abstract] - Two fictional forces (Imperialists armed with French period equipment, Leftists armed with Italian and Soviet period equipment) vie for control of a fictional continent.
Blitzkrieg 1950 [abstract] - Two fictional forces (Great Blue armed with US period equipment, Big Red armed with Soviet period equipment) vie for control of a fictional continent.
Deep Battle 1930 [abstract] - Two fictional forces vie for control of a fictional continent. Similar to the above Blitzkrieg scenario, except set at the dawn of Soviet “Deep Battle” doctrine.
Anonymous Heroics [abstract] - Two fictional forces both armed with Soviet equipment circa 1943 vie for battlefield control, with equally balanced forces and terrain.