en passant is a legal move like castling or pawn promotion. It should be legal anywhere you play standard chess.
En Passant

No! Why should chess.com allow the French to dictate the rules? They might even tell us to resign our games instead of playing to checkmate!

This subject comes up every few months or so, maybe some clarification?
Yes it is allowed.
To clarify: It is within the rules off chess.

I'm new to chess.com, but not chess, and while a strange capability, imo en passant adds a good extra dimension to the pawn. It logically stems from mideaval pikemen or spear phalanxes ability to engage enemy infantry attempting to charge past.
Of course, one of the main purposes of spearmen were to defend against cavalry, so by logic some sort of en passant should apply to knights as well. However, that would of course completely change the character of a game that has plenty of complexity as it stands.
it is, i've taken en passant, although i've played quite a few people who don't seem to know it exists
If you're speaking about this game http://www.chess.com/echess/game.html?id=45810941, then en passant isn't a possibility since the move was c3-c4. If it was c2-c4 en passant would be possible.

So chess.com does have "en passant", but does not have "lasers"? Is this favoritism of one over the other?

What in the world are "lasers"?
You've been on chess.com for a year and you don't know what lasers are?

No. Do you feel inclined to enlighten me? By the way, a year ago, I was still learning what a pawn was, and how a knight was supposed to move!!

Why do Knights jump in an L formation...I've never seen a horse jump like this....Shouldn't they rather jump in an ''n'' type move ? or maybe ''m'' formation like a double jump or something.

Thanks Oinquarki, a long article, but no mention of chess that I could find.
It must have been vandalized. Lasers play an integral role in Mongolian Talibillichess.

No. Do you feel inclined to enlighten me? By the way, a year ago, I was still learning what a pawn was, and how a knight was supposed to move!!
You are to be commended for your honesty, as well as going from learning what a pawn was, just a year ago, to contributing and perhaps also playing on Chess.com. I don't know what a "laser" is either, at least as applied to the game of Chess. Regards, carokannfan
Thanks for your kind comments, carokannfan. I appreciate them. I suppose I shouldn't have come on this thread and asked a silly question if I didn't want to get my leg pulled.
Is En Passant legal on chess.com??