I want to start a new project, there are currently 4 of us who plan to use the system as our website. So basically i'm wondering if there are any existing frameworks/libraries that will enable to us to build the app to be configurable. Kinda like how wordpress is, you can add your own theme and plugins to customize the functionality of the site. I don't want to use an existing cms such as joomla or a blog like wordpress because I want to be building my own app from the ground up.
If there aren't any frameworks that can do this, any suggestions on how i could go about accomplishing this? In essence i suppose its allowing the app to have a default theme then have that theme overridden and allowing use of "plugins"