I\'m about to start work on a new project and thought it could be a good time to also start looking into a new PHP CMS. I\'ve really only spent a lot of time with Joomla, so \"n
There is also a new library: http://phpabtest.com which should serve your purpose.
Aren't these types of tests more on application level? I have never seen any php framework support it anyway :)
But if you need a suggestion for framework... Yii, Lithium, Zend Framework, Symfony are all good choices :)
If you're looking for a framework that's designed for eCommerce with A/B testing, then Magento Commerce has it built in using Google Web Optimizer. There is an interesting article here on the results of such an experiment.
As you'll quickly find through the google, Magento is not for the faint-hearted, but does offer some serious benefits.
Enjoy, JD