Minetest is now called Luanti is a free software game, which is very similar to Minecraft. The Tuxiversity project is running its own game server, which can be used to learn the game, and you can also collaborate with other users.
In addition, using the Lua programming language, you can develop your own scripts for the game.
Hopefully in time, people can run their own servers and games, which will teach some superb skills during this process.
References
Luanti