I created the "Floft Website Builder" a while ago that I used to use for this website (which is why I majorly updated it a few months ago), but I then switched to using Drupal since my way of creating plugins really wasn't planned out. On some websites that I host, they still use the editor. Here is the list that I can think up off the top of my head:
Rose of Sharon
Sing a New Song to the Lord
If you really want the code, it still can be updated and everything, you just have to get the installer for it. You have to have MySQL and PHP for this to work... but, if you want to try it out, you can download the "installer" from:
http://www.floft.net/uploads/designer/webbuilder_installer.zip
And, if you want to see the documentation that I wrote up once, you can look at: