| Debian / Ubuntu | sudo apt-get install git-core |
| Fedora | sudo yum install git-core |
| Windows | Download and install msysGit |
| OS X | Use the git-osx-installer |
See the git page for the most recent information.
Have a look at the github install help pages available from github help
There are good instructions here: http://git-scm.com/book/en/v2/Getting-Started-Installing-Git
