What's the longest opening?

What's the longest opening? (by # of moves and by name)

A05 Reti

1.Nf3 Nf6

2.Ng1 Ng8

3.Nf3 Nf6

You get the idea

1.Nc3 Nc6 can get same A00 Dunst

Well, this one is not so long cuz U'll get a draw by repetition. 

However, avoiding trivial repetitions, one can easily get an opening as long as U want.

Well, here I easily created an awesome opening in 30 moves :

I'm guessing the Colle system.  Five pawns move and seven pieces move.

Seems like different people are understanding this question differently. I was imagining some line in the Ruy Lopez, Najdorf, King's Indian, or Grunfeld, where grandmasters are still in book on move 40.

The higher ECO codes A99 Dutch, B99 Najdorf, C99 Ruy Lopez, D99 Grünfeld, E99 King's Indian Defence all run above 20 moves of theory.

Probably the Botvinnik variation in the Semi-slav

B33 Sveshnikov, B78 Dragon, C80 Open Ruy Lopez, C89 Marshall also exceed 20 moves of theory.

the forum question is ambiguous.

#11
An unambiguous formulation would be:
What opening has the longest sequence of identical moves played in two distinct grandmaster games?

The Spanish opening theory goes on for so long that I bought a book entitled SPANISH WITHOUT a6