If you want to see the backend you can go to our documentation page and review some screen shots as well as a number of other informatin.
You can also download the latest eval distribution - install it and then actually develop against it aas well as connect up DNN directly to your own copy of the ECF. Then you can see, play, develop, integrate and test it all out including the backend.
You can check out this little quick guide that gives you some ideas on paths to getting going with the ecf quickly.
http://www.mediachase.com/ecf/newtoecf.aspx