What is XAMPP? #
XAMPP is free server software. It allows you to run programs that were built with coding languages designed to run on a server. Such as PHP.
Where to download XAMPP #
You can can download XAMPP for Windows, Linux or OS X from ApacheFriends.org. Download the package that is correct for your operating system.
Note: I will only be able to provide setup instructions for Widows and Linux. However, the installation process should be very similar for OS X.