Setting up on Linux.

[fodah]

I use last version, that is to say Ubuntu 12.04. Why this question ?

I only tried to play in localhost, i didn't tried to play online with friends.

I like C++ too, but implemanting game like Minecraft in Java may be easier than in C++ no ?

Oh I was just curious. Of course running a server with java is easier, as the java server software is provided by mojang. From a technical standpoint, it may be easier in the short term to use java as a platform, but in the long run java is always going to be much less efficient than any language that runs directly on hardware without the JVM.