Web scrappers are simple programs that are used to extract certain data from the web.

Cache is a programming concept that can be used in a various range of applications and for various purposes. A cache library can be used for storing database queries for later use, to store rendered pages to be served again without generating them again, or to save indexed pages in a crawler application to be processed by multiple modules.

URL handling is one of the tasks you have to do from time to time in PHP. Sometimes you have to do it because you want to record the referral sites, other times because you want to write your own spider or just because you want to retrieve your current URL.

Alexa does not offer any free API to obtain Alexa Rank. This tutorial presents a simple method to obtain it in the same way the Alexa Toolbar does.

The model view controller pattern is the most used pattern for today’s world web applications.