PlantUML
PlantUML is the workhorse of software UML — sequence, class, activity, state, and component diagrams from a text language that has accumulated two decades of examples, which is precisely why LLMs are so fluent in it. It has no JavaScript renderer, so livefigures renders it through a kroki endpoint (self-hostable for private diagrams; network is needed only on cache misses). Figure 1 shows this extension’s own render flow as a sequence diagram. Click to zoom.
