I neede to draw some sequence diagrams. Many people use presentation software like LibreOffice Impress or drawing software but I’m lazy and slow with those programs. Let’s add that I want to use them in a reveal.js presentation. So I asked DuckDuckGo, discovering https://github.com/denniskniep/reveal.js-plugin-sequence-diagrams which uses https://bramp.github.io/js-sequence-diagrams/. The latter in particular is really a smart piece of software!