Forge Networking [Unity Engine]
In short, Forge Networking is a free and open source multiplayer game (multi-user) networking system that has a very good integration with the Unity game engine. You wanna make a multiplayer game or real time multi-user application? This is the library for you.
Welcome to the most innovative networking solution (which works with the Unity game engine). Forge's network bandwidth is unbeatable, its performance outclasses other solutions, its flexibility is in a league of its own, and, as always, it has no CCU limits whatsoever. Forge Networking is an open source networking solution built in C#. It is completely multi-threaded and was designed to work both inside and outside of the Unity Game Engine but mainly in conjunction with Unity. To get started, check out the links listed below in this readme.
Unity multiplayer games/applications
Unity independent applications
User hosted servers
Run servers on Windows, OSX, Raspberry Pi, and/or Linux
Developer hosted servers
MMO, RTS, FPS, MOBA, you name it, Forge does it
Master Servers, NAT Hole punching, Web Servers, Cache servers, all the servers!
Server to server communication, yup
Spin up servers on demand, check
Tons of other stuff that I won't list otherwise I will go on forever, yes indeed
If you can name it, Forge most likely can do it :), it is built on some basic principles which makes any idea a possibility.