Freeminer!

Minetest is a near-infinite-world block sandbox game and a game engine, inspired by InfiniMiner, Minecraft, and the like.

Terasology (started under the name Blockmania) is an open source project started by Benjamin “begla” Glatzel to research procedural terrain generation and efficient rendering techniques in Java using the LWJGL. The engine uses a block-based voxel-like approach as seen in Minecraft. After proving itself as a solid tech demo begla was joined at first by Anton “small-jeeper” Kireev and Rasmus “Cervator” Praestholm and a full-fledged game concept was born.

ROBLOX is an online virtual playground and workshop - where kids of all ages can safely interact, create, have fun, and learn.

The Fun-Focused Free Software Voxel World Game.

In a galaxy of procedural worlds made entirely from LEGO bricks, will you...

Mythruna is a game under construction combining extensive world building, crafting, and sandbox elements with just a touch of role-playing. When completed, Mythruna will be a unique gaming experience.

A completely clean-room implementation of Minecraft beta 1.7.3 (circa September 2011). No decompiled code has been used in the development of this software. This is an implementation - not a clone. TrueCraft is compatible with Minecraft beta 1.7.3 clients and servers.

You are marooned on the shores of an infinite blocky world. Explore, mine resources, craft tools and weapons, hunt and make traps. Build a shelter to survive nights and share your worlds online. Possibilities are infinite in this sandbox survival and construction game.

Creativerse is a sandbox adventure game set in a beautiful yet treacherous world shrouded in mystery. Adventure solo or bring your friends, unearth secrets, and tame the land together!

Night is falling and your blockhead is freezing. You haven't yet made shelter and your campfire has gone out. All you have is a spade, some wood and a few sticks. You have only minutes before exhaustion hits. Do you create a bed, dig a cave or refuel your fire?

Blockland is a non-linear sandbox game with no set goals, giving players the freedom to design and construct elaborate structures. Styled as a tiny minifigure, players build inside of the virtual world using bricks reminiscent of toy blocks. These structures can be built in either a single-player or multiplayer (either online or through a local area network) setting.

Expanding upon the immensely popular action-sandbox title Terraria, exploring what might have been, and approaching gameplay in a new direction; Terraria: Otherworld represents a novel take on the Terraria experience.

Minecraft Clone to PSP