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The industry-standard open-source library for building visual programming interfaces.

PlantUML is a versatile, open-source component that allows users to create UML diagrams from a plain text language. Unlike drag-and-drop tools, PlantUML follows the 'Diagrams as Code' philosophy, enabling version control, peer reviews, and automated generation within CI/CD pipelines. Technically, it relies on a Java-based engine and the Graphviz visualization software to calculate layout and rendering. By 2026, PlantUML has solidified its position as the enterprise-grade alternative to Mermaid.js, offering significantly more complex modeling capabilities, including support for C4 models, Archimate, Gantt charts, and mind maps. It supports an extensive array of output formats such as SVG, PNG, LaTeX, and EPS. The architecture is designed for high extensibility, allowing for custom skinning via 'skinparams' and the inclusion of external sprite libraries. Its ecosystem is vast, with native integrations in virtually every major IDE (VS Code, IntelliJ, Eclipse) and documentation platform (Confluence, Jira, GitHub, GitLab). For organizations prioritizing long-term documentation stability and technical depth, PlantUML remains the definitive choice for mapping complex microservice interactions and enterprise systems.
Built-in support for the C4 model for software architecture (Context, Containers, Components, and Code).
Verified feedback from the global deployment network.
Post queries, share implementation strategies, and help other users.
Supports !define, !include, and !ifdef directives similar to C-style preprocessors.
A sub-tool within PlantUML specifically for creating low-fidelity UI wireframes using text.
Automatically renders complex JSON or YAML data structures into readable tree or object diagrams.
Integrates JLaTeXMath to allow mathematical formulas within diagram labels.
Native support for the ArchiMate enterprise architecture modeling language.
Extensive library of icons (AWS, Azure, Kubernetes, etc.) that can be embedded as macros.
API documentation frequently goes out of date as code changes.
Registry Updated:2/7/2026
Visualizing complex asynchronous messaging between 50+ services.
Communicating ERD changes to non-technical stakeholders without manual drawing.