Contao is a powerful open source CMS that allows you to create professional websites and scalable web applications.
Con­tao is com­pat­i­ble with Var­nish and oth­er HTTP caches and it sup­ports mod­ern tech­nolo­gies such as HTTP2, de­ferred im­age re­siz­ing and ESI. Even with big in­stal­la­tions with hun­dreds of thou­sands of pages, Con­tao re­main per­for­mant and de­liv­ers your web­site in a flash.
Highly customizable
Thanks to hooks and events, you can ma­nip­u­late the pro­gram flow in var­i­ous places. In­sert tags al­low you to em­bed dy­nam­ic con­tent any­where. And even if you up­date Con­tao, your cus­tomized tem­plates will be pre­served.
Versatile. Mobile.
In­di­vid­u­al, search en­gine-friend­ly and bar­ri­er-free de­sign im­ple­men­ta­tion for desk­top, tablet, and smart­phone.

Back-up Link: Contao