Package dia

Diagram drawing program

https://wiki.gnome.org/Apps/Dia

The Dia drawing program can be used to draw different types of diagrams, and
includes support for UML static structure diagrams (class diagrams),
entity relationship modeling, and network diagrams. Dia can load and
save diagrams to a custom file format, can load and save in .xml format,
and can export to PostScript(TM).

General Commands (Section 1)
dia
Dia is used to create diagrams. Dia has a number of basic tools, like lines and boxes but can also dynamically load sheets. A sheet is a collection of tools...