If you intend to run multiple Kohana applications from the same code base, the separation of the system & modules directories from the application and it's themes is the standard way to go....
While working on converting old and flaky code to our current framework, making it more object orientated, with less duplication and easier to understand and use I thought I'd cover a few things which to me make classes, methods and interfaces "Programmer Friendly"....
morePHP has the ability to type hint function arguments to only accept that type or derivatives of that class or interface, this can lead to better interface design and much less runtime checking (as calling a type hinted function implicitly requires the parameter be of the correct type)....
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