So people can start coding their own servers.
The concept might be a bit complicated to explain but I'll do my best. I'll draw on an example from another field of software engineering -- chess engines. Long since, the effort to join both the UI and the chess engine (that actually plays the chess itself) was abandoned in favour of a communication protocol, via stdin and stdout. Whereby the chess engine has no visual front end and just communicates with UI. Via, for example (and most commonly used) the Universal Chess Protocol. Something similar could be done for Prison Architect.
We'd just need to establish an actual protocol and the developers of PA would have to implement this protocol into PA, whereby it communicates with an external process. In turn, this external process actually communicates across the Internet, to other instances of itself, run by other people.
The communication would consist of basically everything that defines a prison and is required to run it. So, everything in materials.txt, the entire prison and so forth and so on, entity locations, jobs and so forth and so on. Although, obviously, only the PA instance of whoever is running the server would queue jobs and such.
Maybe I'm just being silly but, well... I was brainstorming on a MUD engine in Rust and my creative mind just got the better of me for a moment.
At least I'm looking forward to feedback. 
