A completely external client working in virtually any aiming based game, proof to any anti-cheat tool you can imagine. More of a script than an ordinary cheat. It's as external (as much as overused this expression is) and non-invasive as an application running alongside of the game can ever be.
Inherently bypasses any anti-cheat there is, the client runs in a similar fashion e.g. a web browser does while playing a game — doesn't interfere (even in terms of reading) with the game's memory in any way.
Supporting Counter Strike Series, Team Fortress Series, Call of Duty Series, Battlefield Series, Day of Defeat Series, Quake Series, Unreal Tournament Series, Borderlands Series and many more. Did we mention any aiming based single player game as well?