Respond is an open source, responsive content management system that you can use to build responsive sites. Respond features a REST API, a lightning-fast Angular-powered UI, Bootstrap 3.0, multilingual support, and an enhanced data layer using PDO.
Learn more about Respond CMS at: http://respondcms.com
View our documentation at: http://respondcms.com/page/documentation
The current version is Respond 4.