Since most people now heard of Minecraft
and its unbeliveable commercial success, Minecraft clones are popping out everywhere on the web, implemented in various languages and using lots of different technologies.
For example celeron55 created Minetest c55
using the Irrlicht 3D engine
, and it looks like this:
Runs on Linux and Windows, features multiplayer support and is very fast. Nice project :)
I think the reason for all those Minecraft clones is not that people think they can also get a lot of money out of this (they wouldn't anyway), but that it is a nice programming challange: You don't need a 3d artist and the algorithm for rendering and doing game logic in that 3d world is quite fun, from a programmers point of view.
But I think it won't be long until commercial, big money funded Minecraft clones with non-programmer-art graphics will see the light. Sadly, game development today is mostly merging together two or more already existing game concepts which worked before. Will be interesting to watch what the big players will make out of this, and I hope to see them fail. :)