Git is a source control and versioning software that has become very popular over the last few years. In February of 2011, drupal.org migrated from the outdated CVS versioning system to Git. The migration to Git has enabled a completely new way for Drupal developers to interact with drupal.org, and we will highlight this enhanced interaction throughout the book. However, we will also immediately start using Git to facilitate setting up a Drupal development environment. So, if you don't already have Git installed on your computer, let's get it set up.