This is a web crawler designed in PHP, based on the web crawler shown in this Stackoverflow answer. However, for my purposes, I found an iterative approach to be more effective than the recursive approach. If you throw the project up on a server, you can parse websites for any PCRE pattern, and to any set depth, with any starting webpage, using the provided UI.
Download this zip, unzip it, host it on a server or on localhost, navigate to the default.htm file on any web browser, input your paramaters and crawl away!
If you don't know how to host it, I suggest using XAMPP. you can find a good tutorial on XAMPP here.
If you want to learn more about PCRE regexes, the PHP manual is a good place to start.
This plugins is not licensed. Please don't claim my work as your own unless you modify it. I do not condone Denial of Service attacks, or any mischievous, malicious, or otherwise ill-meaning use of this software.