I currently have several projects on the go which may interest you. You can find there details below.

BackendPro

BackendPro is a control panel for developers written in PHP for the CodeIgniter framework. Its not like a CMS where it provides you with a full working system but it does provide you with part of a system.What I mean by this is it provides you with functionality to do all the simple repetitive tasks like authentication, permissions and a basic look and feel for your websites control panel. So using your current PHP and CodeIgniter knowledge you can use BackendPro to build a fully working website quickly since you can concentrate on your application instead of the bits to manage the system.