It usually happens to me with the knights out first, but it pretty much allways transposes into the same line. I'm assuming white most likely wants to head into a colle opening, and I really haven't gotten a clue on my ideas here. I understand that white wants to push e3 and get a crude kingside attack going usually, but what is black to do?

I usually counter this with an early c5 myself, trying to take the iniatiative but it usually goes ape. I had a (rapid) game in this variation just recently where I got crushed after some early misstakes and not getting the pawn back after he snatched it and tried to hold into it. I'm starting to doubt my early c5 here, what is the usuall line for black? What is the equalising line for black which I'm sure exists in the colle.

Gee, I'm already regretting creating this thread, why create a thread about it when I could just google and research it on my own? Anyhow, I might learn something in this thread that I won't on wikipedia.

Or maybe have a look into Game explorer ?

I usually castle early, develop my pieces, then play ...c5 late to open up the position.  Here is an example game I played here.

c5 is quite good. I also play that. Your mistake must be later.you generally want to combine this with a quick qb6, shifting the focus to the queenside and trying to put black on the defensive, which is generally what happens. Speed is important, becuase if white is left a free hand he can just do a lazy, simple kingside attack setup with Ne5,f4,0-0,rf3,etc etc. that happens to be difficult to handle. Sometimes you want to advance the pawn also to c4, which is unusual in most positions to give the opponent a lever, but often in this case it works becuase you take initiative. It requires fairly energetic and creative play to treat the opening this way. Of course there are many easier solid ways black can play where white really should not get much. This is not a terribly critical, or interesting opening so you probably wont find much good info about it, its better to ask about it here imo heh

Yeah, google and whatnot didn't really help alot, except to describe what white wants to do if black takes no action to stop it.

Interesting replies so far.

An offbeat thing to try is Bf5 attempting to enter a semi-slav, which is what I usually do.  Primarly because it makes someone I know want to murder me for spoiling his fun.