Hub is a command-line script created by Chris Wanstrath, designed to extend the functionality of certain Git subcommands by incorporating GitHub-specific features. It enables users to perform tasks like cloning repositories with enhanced options and adding remotes more efficiently, while remaining safe to alias as "git" in the shell. Installation is straightforward, involving downloading the script and adding it to the user's system path. The tool requires Ruby versions 1.8.6, 1.8.7, or 1.9.1 to operate, and further details can be found in the README or the man page. Hub invites contributions from users and aims to streamline Git operations with GitHub integrations.