I've actually worked with the Public Knowledge Project for many years, so just to shed a little light on the PHP framework that we use: Alec Smecher, our lead architect, has gone on record several times as saying that "the last thing the world needs is another PHP framework".
It came from the organic growth of several parallel applications (OJS, OCS, the OAI Harvester, and now OMP) sharing code, which we decided to abstract into a common layer to improve maintainability. It was never intended to be used as a standalone framework, although people have done so with great success. It does have some great features (namely excellent corss-platform and PHP4 compatibility) but I probably wouldn't recommend it over any of the other, dedicated PHP frameworks mentioned in this thread.
A cautionary note: try to be clear about your requirements from the outset when choosing a PHP framework, as in my experience (with Zend, CakePHP, Symfony, CodeIgniter and YII) there is often a trade-off between complexity and things like speed, PHP4 support, etc. Very little is as frustrating as using a heavy, highly-featured framework when you just need to cobble together a quick prototype on your laptop.
On 2010-11-15, at 6:19 AM, David Kane wrote:
> I am interested to hear if anyone is using PHP MVC frameworks to help with
> their code. From what I have learned, they seem to be a very good idea
> However, there are so many of them (http://www.phpframeworks.com/)
> Also, pkp.SFU.ca uses their own one in their PKP (public knowledge project)
> Who is using them and what for?
> David Kane, MLIS.
> Systems Librarian
> Waterford Institute of Technology
> T: ++353.51302838
> M: ++353.876693212