* offline
    * Service Worker: [[https://developer.mozilla.org/de/docs/Web/API/Service_Worker_API|..API, mozilla]] [[https://github.com/mdn/sw-test]]
    * [[https://developers.google.com/web/fundamentals/codelabs/offline/]]
  * PHP/DOM: [[http://simplehtmldom.sourceforge.net/manual.htm|simplehtmldom]]