Diagrams.net
Diagrams.net is an open source, online usable diagramming software.
The RPTU offers Diagrams.net purely web-based. You need to be inside the RPTU LAN to use the software. A
This service is offered without content support by RHRZ.
In the "Help" menu of Diagrams.net you will find links to support as well as to a qick start video.