On the Zend Developer Zone today there's a new post showing how you can cache your application configuration file to boost the performance of your Zend Framework application just a little bit more.

If you think that you've done everything in terms of performance optimization of your Zend Framework-based project, I bet that your application configuration file was not included in that process. [...] Reason why I'm referring to application config is that its parsing is performed on every request, which is certainly unnecessary, as you don't make configuration changes very often. Solution is simple - cache it.

He opts for an APC-based solution that, in the bootstrap, reads in the configuration file and caches it as a part of a custom Zend_Application object. Code is included for both the addition to the bootstrap and the custom class extending Zend_Application to handle the actual caching.