Let's get the semantics out of the way first.
I think that the definition of a "framework" is a system of
"pre-cooked" code that can be used to build websites but
not actually a website itself, out of the box.

By those terms of reference,
WordPress, Joomla and Drupal are NOT frameworks.
They are CMS because out of the box they all provide
a working website that can be adapted and built upon.

The major PHP frameworks that I know of are
Zend, CodeIgniter and CakePHP.

The first one, Zend, is kind of the mothership of all PHP frameworks.
It's run by the guys who started the whole PHP project, so it has
rock solid credentials and you know its going to be around for ever.
If you want to get a job working on enterprise size PHP systems, I think Zend Certification is a must.
Having said that, it's kind of overkill for most freelance developers or hobbyists working on small to medium size projects.
It has a large code footprint (about 28MB I think) and your host will
need to provide SSH access to run the necessary command line functions.
Setup is a bit labourious I believe.

As for the other two, CodeIgniter and CakePHP, I'm sure they are both good systems and each has its strengths. Both are far more lightweight than Zend (e.g. CI has a code footprint < 2MB, I believe). And you dont need command line access for either.

The CodeIgniter project seemed to have some organizational problems a while ago but it looks like they have sorted those out now. The project has been moved to GitHub and they are crowdsourcing patches and improvements so future development looks assured.
If good old Google Insights is any guide, CI would seem to be on a promising growth trajectory, which is surely one important factor to consider before investing your time to learn any framework, CMS or ecommerce package.
http://www.google.com/insights/searc...cakephp&cmpt=q

Hi, i'm new to this forum and i must say that i have read all the posts regarding this php framework suggestion.
After i've got some skills in php, and watch how much files and bugs are in my files i give it a try to simfony but i must say that the installation took just 4 hours i sayed...hmm if the installation took 4 hours how about the code, then i just jumped on Codeigniter, and i've found it very easy and yet powerfull to my needs, the main reason (i think ) that people choose CI it's that the forum it's very helpfull and if you have a problem there'r a lot of people avail to help you, but that's not all, CI has a great well structured Documentation, i know that many frameworks are just givin' a heads up to initial you into theyr framework. Anw at the bottom line CI it's awesome and simple.
But i'm not so sure about any CMS, becouse if you work as a freelancer you don't have 2 similar projects where you can use that cms twice, but the main scaffolding will help you to skip some basic points like registration, login etc, a great plus.

the igniter is one of the best of his type, the database driven type, have you guys tried application oriented ones?

What about FatFreeFramework ?
"The philosophy behind the framework and its approach to the Model-View-Controller design pattern is towards minimalism in structural components, avoiding application complexity and striking a balance between code elegance, application performance and programmer productivity."

The free ones are ok, but the paied ones are reeeealy good.

If you work somehow with web development you HAVE to use one to improve your coding time.

ylly have you ever tested one?

As per my experience CakePHP is most easiest framework to start and work

If you new with php framework, i prefer CodeIgniter, then cakephp,

if team, i prefer Zend Framework,

and If CMS, it is Drupal. ( i like it too.)