Adventure Game Studio (AGS for short) allows you to create your own point-and-click adventure games, similar to the early 90's Sierra and Lucasarts adventures. It consists of an easy-to-use development environment, and run-time engine.
The game interface is fully customizable, although the classic Sierra interface is supported by default. You need no programming experience to make a game using AGS - setting most game options is just a matter of point-and-click (though scripting is of course available if you prefer). AGS manages most of the game so that you don't have to - it provides load/save game functions, inventory management, and more.
Add in some interactions (ie. what happens when the player clicks on various things) and you're done. You can even create a standalone EXE file containing your entire game, which you can then distribute.
(Taken from their website)
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