[Discere]

I have been using DOT diagrams a bit recently - https://en.wikipedia.org/wiki/DOT_(graph_description_languag... - I like it because I can put into source control too

[Jtsummers]

PlantUML is a cool tool that will generate a lot of the types of diagrams programmers and system designers might like to make and see. Plain text descriptions of the diagrams turned into images. Some of them you could do directly in DOT syntax, but not all or not as easily.

http://plantuml.com (I do, however, seriously dislike how many ads are on the site for this thing)

[krueger71]

Good tool that is often enough. Text-based means version control. I'm using it via a plugin in Visual Studio Code. Very lightweight solution.