It is basically a WYSIWYG EDITOR script that you can use to start your own website builder, that your users can use to generate simple websites.
Check out the script
Sites made with PHP Beaver
Intuitive, drag and drop interface
Generates sites with custom elements (Navigation bar, Secondary navigation bar, Content boxes, Sliders, Contact forms, Share plugin, Footer etc)
Generates responsive sites
Generates sites with custom themes (Bootstrap skins)