Mirror: https://openingh.ypid.de/netzwolf_mirror/ Repo: https://github.com/opening-hours/netzwolf_mirror
Netzwolf has been very active in the early days of Key:opening_hours and hosted resources and tools at http://www.netzwolf.info/ which now, (2017-10-03) only returns HTTP 451.
This repository hosts a small subset, namely the JavaScript library for Key:opening_hours by Netzwolf and his HTML interface for the library.
Note that this is not maintained anymore and meant as a reference only. Refer to https://github.com/opening-hours for ongoing development.