mermaid-js/mermaid

Mermaid is a JavaScript-based diagramming tool that generates diagrams from markdown-like text definitions. The tool renders flowcharts, sequence diagrams, UML diagrams, mindmaps, and other diagram types from simple text syntax, addressing the problem of documentation falling out of sync with code. Rather than requiring developers to maintain diagrams manually or use complex graphical tools, Mermaid lets users define diagrams as text that can be versioned, reviewed, and modified alongside code. The approach works by parsing text definitions written in a markdown-inspired syntax and rendering them to visual diagrams, making it possible to keep documentation current without the overhead of traditional diagramming tools.

Mermaid suits teams that want diagrams embedded in their documentation workflow without friction. It works well for projects using markdown-based documentation systems, wikis, or version-controlled repositories where diagrams need to stay synchronized with code changes. The tool is accessible to non-programmers through its live editor while remaining scriptable for developers who want to generate diagrams programmatically. It integrates with GitHub and many other platforms, making it practical for teams already using those systems.

The project shows substantial real-world adoption, with almost all open issues coming from external users rather than the core team. Responses to issues and pull requests typically arrive within one to two weeks. The issue tracker is dominated by bug reports and triage work, reflecting an active maintenance posture focused on stability and addressing user-reported problems.