Most hotel PMS have their own api called an interface. Micros Fidelio (Opera) is the most common hotel PMS out there. There are alot of other hotel PMs out there but alot copy the Micros Fidelio interface spec so if you can get your software working with that interface you should be good with alot of vendors. Just to note each vendor has their own costs associated with letting third parties interface and some are not cheap.

Thanks for your answer. I have been looking at lots of hotel solutions. They seem to be integrated with PMS, GDS etc. They all have very low pricing as well. I can't seem to figure out how they have done this. If you have more information, that would be helpful. Thanks again.

Yeah there are lots of different interfaces for each PMS. For example take Opera by Micros Fidelio. They would one interface for phone billing, one interface for mini bar billing, one interface for GDS, for POS, for in room entertainment, for phone maintenance (enabling disabling n room sphones etc), for in wifi billing etc etc etc. So Basically one PMS will have multiple interfaces each for specific purposes. I have no idea what solution you are thinking about but lets say you were thinking of providing wifi to a hotel chain(for the purposes of our example). Now the hotel chain use Opera as their PMS. So you get the spec for that specific wifi billing interface. Then you pay them for the access to the interface and a test system and then you would write your code to enable your system to communicate to that interface. It all goes thru their testing in their mothership and its either approved or denied etc etc etc. Its a slow. process.

Not sure if this is any help to you. I understand why you might be apprehensive about giving more specific details in your scenario but without that Its hard for me to be more specific and hopefully more helpful in my answers.

Thanks again for your answer. It gives me more direction to investigate and hopefully I would find something that works for me. As you noted, can't divulge too many details: corporate contracts that I signed :) Thanks a lot though!