Start at https://en.wikipedia.org/wiki/Comparison_of_vector_graphics_editors
So, if you have used any such tools (especially on Linux), what are your experiences? And I expecting too much? I have looked at programs like dia. It seems rather basic. But that might just be my knowledge of what it can do. I have also used programs that let you specify the diagram in a text file and it lays out the diagram. That has been fine for simple diagrams. But when the diagrams reach any realistic complexity, the layout is often something that one must struggle with.
I likes Dia. it's real power lay in the ability to create 'layers' that cold show different info about a model. Sadly that's electronic and can't work with hard copy. Yes, out-of-the-box it is VERY basic and as such almost useless. But so was VisiDraw. it just autoloaded a few packages. You _can_ set up Dia to do that too. IIR they were called 'sheets' but were libraries. You could also look at xfig, for a variety of more free-form figures. Xfig is a vector graphics modelling tool which makes scaling easier. https://orng.org/#%F0%9F%8F%A0%F0%9F%94%B8%F0%9F%93%90%F0%9F%94%B8%F0%9F%A4%... https://en.wikipedia.org/wiki/Xfig
All pointers are welcome. I have looked at various discussions of this but they are typically so superficial that they provide no real information. I am willing to investigate alternatives.
-- “Reality is so complex, we must move away from dogma, whether it’s conspiracy theories or free-market,” -- James Glattfelder. http://jth.ch/jbg