MAMP: Mac Apache MySQL PHP
Like the LAMP software bundle, MAMP - Mac - Apache - MySQL - PHP is a great web development platform for Apple Macintosh computers. But, MAMP behaves like a stand-alone Mac application: “MAMP will not compromise any existing Apache installation already running with your OS X. You can install Apache, PHP and MySQL without starting a script or having to change any configuration files! Furthermore, if MAMP is no longer needed, it is sufficient to delete the MAMP folder and everything returns to its original status (i.e. MAMP does not modify any of the "normal" OS X).” The MAMP PRO configuration application makes it extra easy to configure the system, especially virtual hosts.