PlantUML

PlantUML is an open source tool that creates UML diagrams from plain text. It also supports many non-UML diagram types, such as network diagrams, mind maps and wireframes.

You write a short text script, and PlantUML generates the diagram as an image. It handles sequence, use case, class, activity, component, state and deployment diagrams. Output can be PNG, SVG, EPS or LaTeX, and the project also offers an online editor and a browser extension for rendering diagrams on GitHub.

• Sequence, class and activity diagrams
• Export to PNG, SVG and EPS
• Online editor in the browser
• Browser extension for rendering inside GitHub
• Gantt, mind map and wireframe diagrams

PlantUML suits software engineers and architects who document systems in UML. It fits teams that want their diagrams to live as text in the same repository as their code, so they can be reviewed and changed like any other file.

PlantUML is open source under the LGPL 3.0 license and free to use. You can run it locally on your own machine, or use the online server. The browser extension for GitHub is listed as free and asks only for clipboard access. Local use needs Java installed.