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.
Roblox - Reimagining the way people come together.
Terasology - Terasology (started under the name Blockmania) is an open source project started by Benjamin...
VOXELCANVAS - Free online voxel creation platform
Kaedim - Use the Kaedim Platform to automatically transform your 2D art, sketches and photos in 3D.