What is PSR-0?
Very basically, PSR-0 is a recently defined standard for autoloading classes in PHP-5.3.x and above.
If you would like to have a much closer look, a copy of the final document can be found at https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-0.md
I am not going to spend much time on explaining the document or autoloading in general, as that is an exercise best left to the reader, but as a quick introduction to those that have never worked with this kind of thing before, I will explain the very basics and leave it at that.
