I am planning to start using Codeignator framework for all our projections in my company. So I invite all my friends here who are using Codeignator to list the pros and cons of it.
Hi, if I were you I would use Kohana. It is based off CodeIgniter but the main difference is it is in PHP5 and is more lightweight.
oh I never heard abt it.
How is it and what are benefits ?
CodeIgniter will run on PHP 5, however, it’s core is (for the most part) built upon PHP4.
On the other hand, the documentation for CodeIgniter appears to be very good, while Kohana seems to be lacking a bit.
Symfony and Zend Framework are imho the best choices. CodeIgniter is obsolete and I don’t know much about Kohana 
The documentation seems pretty clear cut to me. I wouldn’t compare CodeIgniter to Kohana because its like comparing a father to his child, and obviously the child has evolved. In this case its Kohana basing itself off of CodeIgniter and converting to PHP5 and implementing a more lightweight structure.
I used CI for 1 1/2 years the plus is that it has good documentation,some good “helpers” as you can see and use.
The minus is for example the validation “helper” compare with other frameworks as cakephp and Yii, the active record patern, there is no authentication module (as I know).
You may see at cakephp.org or yiiframework.com before you make your last decision.
[edit]For now there is a (another) poll
CodeIgniter/Kohana are closer to libraries than actual fully-fledged frameworks like zend or symfony.