Just as it's name says - it is a PHP Web service for access authorization. Let's describe it through two examples. Example 1: You have a super cool Web site and you want to stop Web scrapers and similar kinds of it's abuse. With PHP Authorization you can limit the number of requests to let's say 30 requests per IP address per day. Example 2: You have a super cool Web service and you want to make sure that your customers are not making more requests than they have paid for. With PHP Authorization you can set fixed number of allowed requests for each customer and rest assured that no one will get a single request more. Source code included.