Wikipedia:

Luanti (formerly known as Minetest, which is now the default game in the engine) is a community-driven, free and open-source voxel game engine, available on various platforms. Originally, Minetest was a voxel game created in October 2010 by Perttu Ahola to explore the mechanics of Minecraft. Over time, Luanti evolved from the original Minetest game into a general game engine as developers integrated new features.