Inspired by ctemplate, Mustache is a framework-agnostic way to render logic-free views. (As in model-view-controller.)

As ctemplates says, "It emphasizes separating logic from presentation: it is impossible to embed application logic in this template language."

Think of Mustache as a replacement for your views. Instead of views consisting of ERB or HAML with random helpers and arbitrary logic, your views are broken into two parts: a Ruby class and an HTML template.