Just now I successfully tested connecting to a dedicated cloud server with my home computer as well as a friend's! Can't stop grinning! =D
This required me to first move all player specifics like inventory and skills to a per player system which was a big effort on it's own. Previously, anything could just say "add this to the inventory," but now we have multiple inventories connecting and disconnecting freely.
Next was to set up a server-client relationship where the server maintains authority over what players can and cannot do. This is necessary so that a client can't just say "I just dropped 500g." Instead they ask to, and the server checks to see if they actually have 500g before allowing it.
Then came building a dedicated server. A dedicated server uses no graphics and does not spawn a player of it's own, focusing entirely on supporting a game world for others to connect to.
I wrote a small program to act as a master server list, lost some sleep, and threw my back out once in the process, but phase one is cleared!
Phase two will be improving the hosting options, the server list, and getting everything like building and combat synchronized properly. Much easier than phase one.
The final phase three will evolve around enabling infinite terrain, so that players can exist across vast distances from one another. Not an easy task, but certainly not impossible! I'm still hoping to get everything working before Christmas, and will continue to post progress as it happens.