Draw it, write it as code, or hand it to your AI agent: OpenFlowKit is an open-source diagram canvas where the picture and the text behind it are always the same diagram. Drag shapes on the canvas or type a few forgiving lines, and each side regenerates the other as a single undo step. Ten diagram types share that one language: architecture with C4 views and cloud icons, sequence, flowchart, entity-relationship, state, class, mind maps, git graphs, charts, and wireframes. Paste Mermaid, Structurizr, or D2 and it converts into editable shapes, and Copy as Mermaid sends a flowchart or sequence back out for your README. Paste a GitHub repository instead and Map mode draws its architecture for you, with every arrow citing the exact file and line behind it, and a CLI that maps a local checkout for private repos. Connect Claude Code, Cursor, or any MCP client and the agent draws on your live canvas, restyles what is there, and screenshots its own work to check it. A built-in assistant works with your own key from Claude, OpenAI, Gemini, Groq, Mistral, OpenRouter, or a local Ollama, and exports cover PNG, SVG, PDF, JSON, and animated SVG, GIF, MP4, or WebM you can drop into documentation. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.

Technical teams frequently struggle to keep software architecture diagrams synchronized with evolving codebases and documentation repositories. Atlantis Diagrams delivers a unified self-hosted workspace that couples code-driven Mermaid.js diagramming with structured Markdown knowledge bases in a responsive web interface. Engineers can compose flowcharts, sequence diagrams, state machines, entity-relationship models, and Gantt schedules using split-view CodeMirror editors with real-time SVG rendering. An integrated version history tracker automatically captures revision checkpoints across the last 15 document states, letting authors compare modifications and restore previous iterations without data loss. The linked notes environment supports rich Markdown editing, LaTeX mathematical formulas, interactive task checklists, tag indexing, and full-text keyword searches across personal documentation libraries. Canvas controls allow users to pan, zoom, inspect individual nodes, and export finalized graphics directly into vector SVG, high-resolution PNG, or printable PDF documents. Storage engines adapt to deployment scale, running on zero-configuration SQLite databases out of the box with optional PostgreSQL, MySQL, and Redis caching layers for high-concurrency environments. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.