of configurable settings, all of which can be adjusted to meet changing objectives as the scenario progresses. A Tactical Engagement (or TE) is a small scale, hand-built, 'one-shot' mission with a pre-defined objective. The same engine handles the activities of AI controlled units. One of the advantages of building this style of mission is that it allows experienced pilots to practice attacks on high value, well defended targets, which are often eliminated from campaigns early on as the planning AI assigns packages to eliminate them in order to maximise the effect on enemy combat readiness. The Instant Action mode of operation places the user in an F-16 currently in flight, armed with an infinite number of missiles. Progressively more capable waves of enemy aircraft then move in and engage the player's aircraft. Many different options are available to customise this mode, including disabling SAM and AAA defenses, setting unlimited fuel, and the difficulty of the first wave of inbound hostiles. Falcon 4.0 originally featured 3D graphics with multitexturing support. It was one of the first programs on the market which was designed multi-threaded to take advantage of dual-core x86 processors. The game used one thread for graphics and primary simulation and the other for the campaign engine. Development The game was in development since 1994. The game was originally designed and produced by Steve Blankenship and Gilman Louie and published under the MicroProse label. Though originally slated for a late 1996 release, the game ended up being rushed to market in order to make the 1998 Christmas selling season. Source code leak On 9 April 2000 a developer of the game leaked the source code of a Falcon 4.0 version between 1.07 and 1.08 on an FTP site. Digital distribution re-releases In October 2015, Tommo's Retroism publishing label re-released the Falcon series (including Falcon 4.0 as a bonus) via digital distribution at GOG.com, titled as the Falcon Collection, after being commercially unavailable for some years and subject to high, often excessive prices on internet trading sites. In January 2016, Retroism released the Falcon Collection on Steam, with all four titles also available for purchase separately. Falcon BMS (BenchMark S'imulations) is a community-made modification to the already existing Falcon 4.0. The mod, made by Benchmark Sims, is a "complete revision" of the aging game, adding such features like graphics improvements (DX7 -> DX11), 3D cockpits, a newer terrain engine, and multiplayer