Infiniminer

Infiniminer is an open source multiplayer block-based sandbox building and digging game, in which the player is a miner searching for minerals through procedurally generated voxel-based maps and building structures.

Much of the Swedish sandbox game Minecraft draws heavy inspiration from Infiniminer, as is evident by the visuals and mechanics of procedural generation and terrain deformation. The source code was leaked within a month after its first release, and it is now available under the MIT LIcense.