Voxelius

Voxelius is an in-development open-source voxel game with the sole goal to replicate and improve the atmosphere of Minecraft Beta 1.7.3 using modern development tools and practices.  

The game is in very early development but already features things like working multiplayer and semi-decent world generation engine. However, it still lacks some core gameplay features such as gravity, collision detection and player models. 

Join the public test server to try it out:

strato.untode.su:12103