It essentially is its own framework, but if you look at the 3rd party folder you can see that it leverages a bit of zend for search and other open source libraries.

At least that is my understanding. A bit of a hybrid where some mvc c stuff is done in the v (giggity) etc. Models are also not as strict (giggity).

Aside from the unintuitive (at first glance) variable names it is pretty nice to work with.