Good Open Source PHP Projects to study for Learning Purposes

[Kevinmun]

Can anyone recommend some good small/medium open source PHP projects for an intermediate PHP programmer to study for learning purposes?  So far I've been studying primarily sample projects in a couple PHP books I bought.  They were helpful, but some what too simple.  I really don't care what the project is, just as long as it's useful.  Ideally it would be something that's not too simple, but not something that's going to take weeks to go through either. Thanks in advance.

[trq]

Id take a look at one of the frameworks around. Even though they won't show you a working application, they'll teach you allot about how things should be designed. that is of course if you pick a decent one. Zend' is probably too large to start with, codeigitor is written in php4.... maybe Kohana?

[Kevinmun]

Id take a look at one of the frameworks around. Even though they won't show you a working application, they'll teach you allot about how things should be designed. that is of course if you pick a decent one. Zend' is probably too large to start with, codeigitor is written in php4.... maybe Kohana?

 

Thanks for the tip.  I'll look into Kohana.  I've been considering learning Zend Framework in part because there seems to be a lot of documentation and books about it.  I'm big on books. 

 

But really I'm looking for a complete working project.  The areas I'm particularly interested in studying are a full-featured user management system, security, & code organization.  The other downside of the PHP projects I studied in books is that they were basically just PHP, HTML, & CSS.  They didn't contain any Javascript, AJAX, XML, etc.  I would like to find a project that contains all of these technologies.  I'm familiar with these technologies already, but I just feel like I could use some help with organization & design.

 

I was considering Zen Cart but now I'm thinking it may be a little too complex for me.  Thoughts?