Minecraft is sandbox world building game currently owned by Microsoft.

Dwarf Fortress (Slaves to Armok: God of Blood Chapter II: Dwarf Fortress) is a part construction and management simulation, part roguelike, indie video game.

StarMade is an almost infinite open-universe space simulation sandbox game.

Voxelands is a free voxel world game.

Minetest is a free, open source building game inspired by Minecraft.

Gnomescroll is an open source multiplayer voxel game.

Manyland is a browser based game.

Terasology is an open-source Minecraft like game.