To avoid confusion: It's not the Minecraft voxel engine, it's an independent voxel engine which can be used to create Minecraft-like games. The engine itself is

To avoid confusion: It's not the Minecraft voxel engine, it's an independent voxel engine which can be used to create Minecraft-like games. The engine itself is written in C++ and its game API is mostly in Lua. This API is also the modding API, so you can really change up essentially all content with mods. And technically, games created with it are essentially just modpacks. There's also a reference implementation, which you can download and play without getting into programming. It doesn't have all too much content by itself, but you can extend it with mods or use it to connect to multiplayer servers which can have their own collection of mods (sort of Modpack-as-a-Service). So, you should also quite easily find a multiplayer server which has some form of currency and economy.