I guess im wondering why you would not have a simple gateway option that ouputs XML? This would make it easy for anyone to build an xml parser so as to implement the payment gateway with any processor??

Sure thing. How about an option called xml output. You would allow us to input the url that we want the packet posted to and provide variables to populate an xml post, in addition to a reply. This way i could pop my payjunction xml into the system, that would then post to my payjunction processor, and i could also pop the reply xml into the system so that cbsubs knows what the response will look like.