Ziker said:
What I'm interested in finding is the libraries and project structures most suitable for use in game dev (server side) and certain techniques specific to building real-time game server.
Network Solutions
I made good experiences with SmartFox Server 2X (link). It is free for less than 100 concurrent users.
You may also take a look at ZeroMQ (link).
Unity
Unity is a fantastic tool for game development, and possibly terrific to create an MMORPG client. However, it is not the right tool to create an MMORPG server.
Books
When you are interested in MMORPG server architecture, you may look at IT-HARE (link). The guy has also published two books that are really worth reading, yet nothing for the faint of the hearth.
Blog
Finally, you might visit my blog (link) on the design and programming of MMORPGs. I just unlocked an article on Scalable MMORPG server architecture (link).
Best Wishes!