Yosemite comes with Apache 2.4 & PHP 5.5 preinstalled. You don’t need MAMP, only MySQL or MariaDB.
Regardless, you can use PHP 5.5, PHP 5.4 or PHP 5.3 as needed. Try the following…
sudo mv /usr/local/bin/php /usr/local/bin/php55 sudo mv /usr/bin/php /usr/bin/php55
Install PHP 5.4
brew install php54 php54-mcrypt php54-mysql
Install PHP 5.3
brew unlink php54 brew install php53 php53-mcrypt php53-mysql
Switch to PHP 5.4
brew unlink php53 brew link php54
Switch to PHP 5.5
brew unlink php54 brew unlink php53 sudo ln -s /usr/local/bin/php55 /usr/local/bin/php sudo ln -s /usr/bin/php55 /usr/bin/php
