The "Run WebVOWL" button at http://vowl.visualdataweb.org/webvowl.html should point to the live demo (currently https://service.tib.eu/webvowl/), but it redirects to https://www.tib.eu/de/ instead. 
The "Run WebVOWL" button at http://vowl.visualdataweb.org/webvowl.html should point to the live demo (currently https://service.tib.eu/webvowl/), but it redirects to https://www.tib.eu/de/ instead.