Sometimes you can do a lot of pawn moves before the pieces, although in general it is a bad idea.
Pure Pawn Openings

You're right, the Advanced Variation of the French had slipped my mind. But it's not exactly the same thing, is it? There is a real strategic purpose to the pawn play, and of course a lot of piece development is just about to happen.
Well, it is not the same thing that his opponent is doing (pushing several pawns reggardless of what is going on). But I guess it was exactly what he was asking for, "a credible opening that have a mainline of four or five pawn moves before devloping pieces".
Of course, no one should start a game eager to move several pawns. It is to be done just on the right situations.
Sometimes I play against folks that just love to bring out all their pawns. Instead of developing pieces, these folks start a slow march of pawns in hopes of getting a positonal advantage by cramping the development of my pieces. I usually am able to still gain an advantage and win, but I was wondering if there are any credible openings that have a mainline of four or five pawn moves before devloping pieces and the theory behind any such openings.
The only one I've found is the four pawns attack by black in response to Alekhine's Defense...BUT ARE THERE ANY OTHERS?