A kind man with great taste in knives who takes excellent pictures?
~ P.
pertinux, if that was directed at me, thank you. It's the nicest thing anyone has said about me all day! If not then I feel like an idiot.

Mark,
My username implies that I should know a lot about the Railsplitter pattern but in all honesty, I know very little facts about it. Elliott (Blues) once told me that it is patterned after the original Surveyor pattern and as far as I'm concerned that is a fact.
My own observations are that it is basically the shape of the handle that defines the pattern. There are several blade configurations on the same frame but all are commonly referred to as Railsplitters. We have the Stockman blade configuration, a couple of different versions of the Moose, and the four blade Colt that smitty44 posted a link to.
Aside from the Colt (which SMKW calls their "Rancher Stockman" pattern) all of the modern Railsplitters that I own and have seen are all made by Queen. Northwoods, Robeson, RAT, Schatt & Morgan, and maybe a few others that escape my mind at the moment. The Northwoods have carbon blades, the RAT has D2, and the others are 420HC stainless as far as I know.
I'm under the assumption that Queen coined the name "Railsplitter" but again, I have no facts to prove it.
The pattern appeals to me in a big way. I remember when I first saw one. Fell in love at first sight and I have acquired 10 more since then. (not all pictured) They feel great in the hand and look great too in my opinion.
Three Schatt & Morgans, a RAT, and a Colt:
One of the Schatt's with the blades open:
An Ivory handled Northwoods Railsplitter Moose. (this one is my favorite)