Main lines Nd2 and b3. Often transpositions may occur.
chessblood (white) vs. ChristianSoldier007 (black) WITH KIBITZERS!
Hahah, I've got more knowledge to share :p
g6 is a move, with Bg7 coming with pressure on e5.
O-O-O!? doesn't have much theory attached to it.
g5!? is interesting. Weakens the kingside, but makes it harder for white to strengthen e5 with f4.
The position after 9. ... g6 10. Bb2 Bg7 11. g3 O-O 12. Bg2 Rfe8 13. O-O Bxe5 14. Bxe5 Qxe5 15. Qxe5 Rxe5 16. cxd5 Bxf1 17. Kxf1 is an endgame which is worth a book itself. If you two want to play this one, I'll be quite amused :D
Okay that might be quite the mistake. I won't give you a concrete variation, figure it out yourself.
HINT: Think about the hanging knight on d5, and pair that with a queen exchange :)
I already suggested a few :p
I just checked that variation again, it's actually possible. But I think after 9. ... d6 10. exd6 cxd6 (10. ... Qxe2+? 11. Bxe2 N~ 12. dxc7) 11. Qxe7+ Nxe7 12. Bf4 black may be in trouble in the endgame due to the bad pawn structure and the bishop on a6 which is biting on wood.
I learned about it in a video by Rensch. He likes playing it as white. Do you want me to post a diagram of it? I kinda want Smit to confirm I'm thinking of the right thing.
Now f3 or nd2? nd2 makes it harder to develop the bishop though.