This guide is intended for developers who want to write and run PHP on their local Mac. It is expected that you have some familiarity with Terminal commands, as well as opening and saving text files with an editor of your choice.
Available from the Apple Developer Center, the Xcode Command Line Tools are all that Homebrew needs to build and install software on the Mac. The Xcode app is only needed if you intend to also to OS X or iOS development.