Writing custom code capable of efficiently retrieving and parsing the XML which comprises a RSS feed can be a difficult and tedious process. Luckily, a number of open source libraries can retrieve and parse RSS feeds for you. Many of these solutions also offer a number of advanced features such as feed caching in order to reduce bandwidth consumption.
For PHP developers, the SimplePie library not only offers the aforementioned features, but also supports both RSS and Atom formats, multiple character encodings, and an architecture that makes integration with your favorite content management and blogging platforms a breeze. In his PHPBuilder tutorial, Jason Gilmore introduces SimplePie and demonstrates how easy it is to create a rudimentary custom RSS aggregator using this powerful library.
All users will need to do is provide the aggregator with a site's RSS feed location, and the aggregator will retrieve and parse the feed, converting it into a format that the user can easily peruse.