Today I learned that the diagram style that shows two or more vertical lines with actions going from line to line is called a sequence diagram, and it’s a UML thing (we never got in to UML when I was in college).
Then I discovered PlantUML, which takes plain text input (like Graphviz dot files), and spits out pretty sequence diagrams, complete with annotations, time delay indicators, and more.
Neat.
Bob->Alice : Knock knock Alice->Bob: Who's there? Bob->Alice: A non-sequitur Alice->Jim: What?
