On NetTuts.com today they've posted a good primer for those that may have heard about the PSR standards that have been introduced to PHP but aren't quire sure what they are (or what they mean to you as a developer).

If you’re an avid PHP developer, it’s quite likely that you’ve come across the abbreviation, PSR, which stands for “PHP Standards Recommendation.” At the time of this writing, there are four of them: PSR-0 to PSR-3. Let’s take a look at what these are, and why you should care (and participate).

They start with a brief history of the standards, the PHP-FIG (Framework Interoperability Group) and where the idea for the PSRs came from. Then the article gets into the details of each:

• PSR-0: Autoloader Standard
• PSR-1: Basic Coding Standard
• PSR-2: Coding Style Guide
• PSR-3: Logger Interface

They also do a good job mentioning some of the criticism that's come with the standards and what sort of future there is including the creation of a standard for a HTTP messaging package.