Rob Allen has posted a quick guide to help you get PHP and MySQL set up on Yosemite, the latest version of Apple's OSX operating system (just released last week).
t's that time again; Apple has shipped a new version of OS X, 10.10 Yosemite. Apple ships PHP 5.5.14 with Yosemite and this is how to set it up from a clean install. However, if you don't want to use the built-in PHP or want to use version 5.6, then these are some alternatives [including the Liip binary package, Homebrew or Zend Server 7.x).
He opts for the Homebrew method, installing it first then getting into the PHP and MySQL packages. This is all done from the command-line, so you'll need to be comfortable there. He includes the commands needed to install PHP, MySQL and Apache along with all configuration changes to make them work together. He also shows how to install Xdebug, PEAR, Composer and the Mcrypt & Intl extensions if needed.