This looks really nice! I can't seem to find a LICENSE file in the repo though, would you mind sharing what license it uses?
That's a very impressive system. I want to find out how they do scaling.
As far as scaling goes, fancy scaling solutions are currently in the 'future-problems' basket. Currently Substrata just uses a naive client-server solution with O(n^2) messaging where n is the number of connected clients - e.g. each message from a client is sent to all other clients. I'm relying on the performance of C++ to manage despite this. I've tested with a few hundred concurrent clients.
Cheers, Nick
1. Big seamless world
2. High detail
3. Fast response
You can get any two of those easily. All three, and you're into a big data wrangling problem. Since I'm working on a high performance client for Second Life/Open Simulator, I have to face all three, and am interested in systems that address all of those.
2) and 3) are the usual case for games - there's a big content download, and then you go. Such systems inevitably have a "Loading..." screen, or screens. Decentraland is 1) and 3); it's a big world, but not much detail. (Each parcel in Decentraland has only 20,000 triangles.) Second Life is 1) and 2) - big, detailed world, big performance problems.
There are some voxel based systems which manage all three, sort of. They have their own problems.
Improbable's system seems to work, but it cost US$400 million to develop and takes huge server resources to run, so the only real customers have been for special events and military training. The five indy games that tried to use it all went broke. (Worlds Adrift was pretty good, too.)
Croquet seems to be a 2) and 3) system.