In addition to the software itself, a Noah's Classifieds installation has the following requirements:
PHP is the programming language in which Noah's Classifieds is written, and is required in order to run the software. Noah's will run on any Php version above 4.3.
MySql database server is required to store the data of the program. Noah's requires a MySql version above 4.1.
A web server is required to send the generated pages to your web browser. Apache web server is recommended and is also the most common one.