PlantUML

Open Source

The industry-standard open-source engine for Diagrams as Code.

Capabilities: Sequence Diagramming Architecture Modeling ERD Generation State Machine Mapping Gantt Charting

9.5

Protocol Reliability Score

Overview

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.