The beauty of Kohana 3, and Zend for that matter, is that they both take a very decoupled and modular approach to their framework architecture. Zend even more so then Kohana 3 since you don’t actually have to use the framework at all, but instead you can pick and choose the specific libraries and even classes that you want to utilize in your application. Kohana 3 on the other hand requires the full implementation of the framework to use any of its libraries, but that’s OK because that’s what it is designed for (being a very lightweight framwork that gives you the structure to build your dynamic web application anyway you need). Kohana expects that you will be using modular components from various places such as Zend and even has an example on how to include the entire Zend framework explained here.
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