Michelangelo van Dam has started a new series of posts on his blog about quality assurance in PHP projects with this introduction and a look at the first tool on his list PHPLint.
Quality Assurance has become an increasing important part of web application development, especially with PHP applications. [...] Luckily there are a lot of tools available that allows you to increase quality of these web applications, and the best part is they are all based on PHP! Let's have a quick look at what tools are interesting to start improving quality assurance on your PHP projects.
The first tool, PHPLint, helps you validate code against syntax errors and is built into the command-line PHP you already have. He describes its use, both on the command-line and in a pre-commit hook on his git repository
For more PHP QA-related information, he also points out the book from Sebastian Bergmann and Stefan Priebsch as a good reference too.