Mermaid

Mermaid is an open-source JavaScript-based tool that enables users to create diagrams and visualizations from plain text descriptions. Its primary purpose is to let developers, technical writers, and analysts define complex diagrams using a simple, human-readable syntax that can be version-controlled and integrated into documentation workflows. Mermaid is widely used in software documentation, wikis, and technical reports to keep diagrams synchronized with evolving code and processes.

Key features include support for multiple diagram types such as flowcharts, sequence diagrams, class diagrams, state diagrams, ER diagrams, Gantt charts, user journey diagrams, and mind maps. Diagrams are defined using a lightweight markdown-inspired syntax, making them easy to edit, review, and maintain alongside source code. Mermaid can be embedded in static sites, documentation tools, and platforms like Markdown editors, GitHub, GitLab, and many knowledge management systems. It also provides configuration options for themes, styling, security (e.g., secure mode), and rendering behavior, as well as integrations via CLI, APIs, and browser-based rendering.