What is Contao?
Contao (formerly TYPOlight) is a free content management system (CMS) for medium to large websites. The program specializes in back-office (i.e. for developers) and front-office (i.e., for users) accessibility, and observes XHTML, HTML5 and CSS standards, according to W3C/WAI guidelines, to generate pages.
The program is an open-source project, published in its original form in 2006 by Leo Feyer.