Leendert Brouwer has come up with a list of PHP applications that he considers some of the best out there and combined them all in a list over on his blog.
Even though a lot of crap applications have been written in PHP, some applications really shine in excellence. Not only are they very usable, they are also coded well, secure, and well-documented. I've compiled a list of applications for a number of genres that stand out in my opinion.
Included in his list are applications like:
- phpMyAdmin for database administration
- JpGraph for graphing and statistics
- Smarty for templating
- Drupal for community and content management









Sunbelt Window Films
http://www.cnn.com/TECH/computing/9910/06/open.source.idg/index.html