Pardon my newbie-ish question, but I've always wondered how to record demos for either or both games, and any games that run off the same engines (e.g. Hexen 2 for the Q1 engine and Heretic 2 for the Q2 engine).
I just ask how to do so. Is there any special program I need? (I saw something I found on Google that said it was used to make them...)