Native macOS app for Mermaid & PlantUML diagrams

DiagramLab turns diagram code into polished visuals—fast. Write Mermaid or PlantUML in a clean, developer‑friendly editor and see the result instantly with a live preview. Great for documentation, architecture notes, UML, and README diagrams. FEATURES • Mermaid + PlantUML support (choose per project) • Live preview: Split / Code / Preview modes • Helpful error reporting with line-focused feedback • Zoom controls for detailed diagrams • Export to PNG, JPG, SVG, PDF, or HTML