An interesting chart comparing various PHP frameworks. I’m not sure that I can read it correctly. It seems to imply that Zend and CakePHP are the most popular frameworks.
Both frameworks are free, but Zend is clearly optimized for the Zend server platform, which isn’t free. Also, I can’t help thinking that the audience is somewhat different for these two. CakePHP seems aimed at the more opensource, DIY crowd while Zend is clearly pointed to the enterprise IT crowd. While there is overlap, you can see that Zend is a commercial venture.
I have very mixed emotions about using frameworks. On the hand, frameworks deliver huge dollops of functionality right out of the box. This accelerates the completion of many IT projects. On the other, you get locked into another group’s development schedule and, to some extent, the architectural choices they make. Projects built with these tools also expose themselves to bugs and security holes originating in the frameworks. Finally, you end up having to trust or vet the code in the framework.
For an inward-facing intranet product, I think frameworks are great. I’m not sure I’d want to launch something like twitter or facebook with one.