I won't make here a full explanation of the "scripting" word, since a lot of information can be found in internet. If you speak french, you can go there to understand what it is [1] ; if you don't, see the file below (thanks to Brian Hook for the permission to post it here) ;-)

For Samoth, we'll use the Squirrel scripting system, an open source "high level imperative/OO programming language".

If you wanna know even more about scripting, then read Alex Varanese's book, Game Scripting Mastery.

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[1] Qu'est-ce que le scripting, et pourquoi s'embêter avec ? (http://www.games-creators.org/wiki/Scripting)