Perch Runway is a comprehensive CMS designed for content driven websites. As a superset of Perch, it shares a template language and much functionality with Perch. Rather than being a drop in solution for making parts of the site editable Runway takes a more typical approach with a front controller and routing to display your pages.
In many cases the Perch documentation should be referred to, this section of the documentation details the things that are different in Runway and any Runway specific functionality. All Perch Add-ons also function within Runway, and some add-ons expose additional functionality when used with Runway rather than Perch.