My preferred Open-Source-Software for diagrams is draw.io (https://app.diagrams.net/ https://app.diagrams.net/). Works great, locally and online and runs on pre

My preferred Open-Source-Software for diagrams is draw.io (https://app.diagrams.net/ https://app.diagrams.net/). Works great, locally and online and runs on pretty much any system while offering everything I need and allowing a crazy amount of customisation.