ClipperCMS is a lightweight CMS and framework ideal for both simple and complex websites. It allows developer freedom and provides many useful features 'out of the box.'
Clipper templates for HTML pages, are just that - HTML. Whatever you can do with HTML, be it HTML4 or HTML5, or XHTML, you can do with ClipperCMS. You are not constrained into set ways of working, or constrained into set formats for your markup.
A strong but lightweight API is provided for development of Extras (add-ons) and bespoke code. A wide range of existing third party Extras is already available by virtue of Clipper's history as MODx Evolution, which ClipperCMS is a fork of.