Simple HTML DOM parser is a PHP 5+ class which helps you manipulate HTML elements. The class is not limited to valid HTML; it can also work with HTML code that did not pass W3C validation. Document objects can be found using selectors, similar to those in jQuery. You can find elements by ids, classes, tags, and much more. DOM elements can also be added, deleted or altered.

They help you get started using the parser, passing in the HTML content to be handled (either directly via a string or loading a file) and locating elements in the document either by ID, class or tag. Selectors similar to those in CSS are available. Finally, they show how to find an object and update its contents, either by adding more HTML inside or by appending a new object after it.

Odds are you [also] need to parse some from time to time: because you consume a web service and want to extract some information, or because you want to gather data from scraped web pages, or just because you want to write functional tests for a website.

The CssSelector tool allows you to convert a CSS selector into an XPath that can, in turn, be pushed into the XPath function of the PHP DOM XML functionality. He gives a few examples of using it for a simple "find" and for something more complex involving a SimpleXML object too.

The library can be downloaded from github here.