PlantUML is a delightful tool you can run online or offline to turn readable plain text descriptions into very-readable visual representations.
It's not just for UML - arguably not even primarily for UML. Here is an example sequence you can make - there are also state diagrams, timing, class diagrams, and many more - there's even a Gantt chart!
@startuml
Alice -> Bob: Authentication Request
Bob --> Alice: Authentication Response
Alice -> Bob: Another authentication Request
Alice <-- Bob: Another authentication Response
@enduml
Of course, you can also get an ASCII rendering. The beauty of these links is that the content is in the URL, so they get generated on the fly and won't rot.
Definitely added to my list of plain text tools I love.
Happy diagramming!
P.S.: important consideration if you're planning on using this at work: Concerning sensitive content: even if we do not store the generated diagrams, please be aware that all traffic goes through HTTP, so it's easy to catch.
Tags: design