DotEditor is described as 'A graphical editor for dot files for use with GraphViz to generate diagrams' and is a Diagram Editor in the category. There are six alternatives to DotEditor for a variety of platforms, including Online / Web-based, Mac, Windows, Linux and Android. The best alternative is yEd Graph Editor, which is free. Other great apps like DotEditor are PlantUML (Free, Open Source), Penpot (Free, Open Source), OmniGraffle (Paid) and Graphviz (Free, Open Source).
PlantUML is an open-source tool that uses simple textual descriptions to draw UML diagrams. The generator can be run anywhere within JVM and integrated with various application such as wiki, text editor, IDE, programming language, documentation generator, and others.
Penpot is the first Open Source design and prototyping platform meant for cross-domain teams. Non dependent on operating systems, Penpot is web based and works with open web standards (SVG). For all and empowered by the community.
OmniGraffle can help you make eye-popping graphic documents—quickly—by providing powerful styling tools, keeping lines connected to shapes even when they’re moved, and magically organizing diagrams with just one click.
Graphviz is open source graph visualization software. It has several main graph layout programs. It also has web and interactive graphical interfaces, and auxiliary tools, libraries, and language bindings.
Code2Flow is an innovative diagram creator that uses simple programming structure to build flowcharts in the most intuitive way possible. It employs syntax from the C programming language in a way that makes it easily usable for non-programmers and programmers alike.