Are older versions of Remote Desktop still avaiable?

My office computer runs Mountain Lion by necessity due to an older software we need to use. I'd like to be able to log in to the office iMac remotely from a MacBook also running Mountain Loin, but the only version of Apple Remote Desktop I see is the newest. I know I can't use Remote Login with Terminal SSH because that requires I have to be on the same network. or is there another solution?