Git and 0.8.1

Anyone know the difference between the two (GIT AND 0.8.1) and where to install git?

To setup the server for the first time, I suggest you first try the released stable version, "0.8.1". And after you are more familiar with how the server works, you can then try the git version.

By "the git version" we usually mean the latest version of the code. Whenever somebody changes the game code and "commits" (i.e. uploads) the code into our code repository, which happens many times a day, a new "version" is created. However, that version may contain bugs, or some experiment that will be thrown away later. On the other hand, if a version is decided by the core team to be suitable for the general public, they "tag" that version with an official release number, such as "0.8.1". The actual git workflow is slightly more complicated than this description. To learn how git works in general, try this. To checkout Xonotic code, read the wiki here.

I'll leave the other question about the changes after 0.8.1 for other developers.

EDIT: I changed the git guide URL. The original link was the technical guide of git's inner working.