Installing PHP versions on Mac OS X Mavericks (10.9+) and Higher
Using Homebrew, Homebrew-PHP and the RVM-like brew-php-switcher you can easily switch between multiple installed versions of PHP on your OS X machine (Mavericks 10.9 to El-Capitan 10.11).
Install the command line tools
xcode-select --install # install the command line tools, if missing
Install Homebrew
ruby -e "$(curl -fsSL https://raw.github.com/Homebrew/homebrew/go/install)"
brew update && brew doctor
Install Multiple PHP versions
brew tap homebrew/dupes
brew tap homebrew/versions
brew tap homebrew/homebrew-php
brew update
brew install php53
brew install php54
brew install php55
brew install brew-php-switcher
brew-php-switcher 55
php -v # verify that it is PHP 5.5
Thanks to philcook and the Homebrew crew!