This example shows a minimal HTML page that renders a small green square using both React and D3. The React component displays the text “compile” inside a div, while a static SVG and a D3-selected SVG each draw a separate rectangle. The code integrates React 16.7, ReactDOM, and D3 5.15 via CDN links, alongside vanilla JavaScript for the D3 append operations. The page demonstrates basic SVG rendering and library coexistence without any interactive behavior.