http://www.realtimerendering.com/erich/minecraft/public/mineways/index.html

Mineways lets you export your Minecraft creations into files you can use for making images, movies, or 3D prints. It is a free, open-source program for exporting your Minecraft models for 3D printing on your own printer or through a service such as Shapeways or Sculpteo, viewing on the web through Sketchfab, and rendering with Blender, 3DS MAX, Maya, Cinema 4D, or other rendering system.

The latest Windows version is 5.09; for Mac it's version 5.04, 32-bit only (read the notes for the Mac). For Linux, use WINE to emulate Windows.

Minecraft is a computer game that randomly generates infinite worlds made up of cubic blocks of various materials, with each block being 1x1x1 meter. There are rules that govern how the world works, but no set goals. Generally you mine the materials from the world, combine ("craft") them into blocks, and place each block in the world to build structures, all using an in-game character that moves like it would in a first-person shooter game. You can play in worlds on your own computer, or with other players on multiplayer servers.

There is more to it than that, including monsters that can get in the way, but I refer you to a few sites that describe it in more detail:

• Wikipedia
• Minecraft wiki
• Rock, Paper, Shotgun
• Penny Arcade comics here and here

A crafting example from the Minecraft wiki.

The game has become quite popular over the past few months. The single Swedish programmer who is developing it has it has over 400,000 paying customers and has made over five million dollars on it so far. And it is only in an "alpha" state!

From my perspective, I find that it appeals to that part of you that loves LEGO, model trains, or building sand castles and pillow forts. I also find it very liberating to be limited to cubes, which sounds ironic. If I had more elaborate or complex tools to build with, the learning curve would discourage me from building something interesting. Only having cubes, I feel much more inclined to dive in and start building.