...pun intended? >:3

Yes! It's interesting that the word when used in that context tends to be spelled differently, even though I think it means the same thing.

I'm not entirely sure of the etymology (and a few minutes of checking didn't clear things up much) but I think originally it was just a second meaning of "come" spelled the same way, and people might have started spelling it differently in order to avoid any ambiguity, or in more modern contexts make sure to keep the concepts separate in text string searches.