Terraria - Dig, Fight, Build! The very world is at your fingertips as you fight for survival, fortune, and glory.
Minetest - Minetest is a near-infinite-world block sandbox game and a game engine, inspired by InfiniMiner...
Minecraft - A block-building game that allows you to create and explore entire worlds from scratch.
Infiniminer - Infiniminer is a multiplayer block mining game with several different player classes to choose from.
Roblox - Reimagining the way people come together.
Voxelands - The Fun-Focused Free Software Voxel World Game.