There are only a few tools nescessary to turn a Mac into a great Rails development machine, and here they are.
Command Line Tools for XCode: Nescessary for Homebrew to compile a few things. Just register for free to download.
Homebrew: A great package manager for Mac, helps you install Redis, Postgres, MongoDB and more.
With Homebrew you can install a few more tools.
Git: Git is the version control system in the Ruby world. Nearly all Ruby gems are available open-source for everyone to contribute to on Github. Install with
$ brew install git. (The
$sign always denotes that a command is intended to be run in the console).
Rbenv and Ruby Build: Helps you install and manage different Ruby versions.
Your developer life can be even easier with these tools.