PlantUML is an excellent tool for creating visual representations of system behaviors. Because diagrams are generated from plaintext, they’re easy to maintain and version control. I use it often when designing new features and systems. You don’t need to pay attention to UML semantics to create valuable diagrams.

PlantUML also integrates pretty well with different wikis. The textual representation is saved in the wiki and the image is generated on-demand.

100% - that’s my primary usage of it. It’s easy to encode complex diagram and change it easily.