A fork of a mouse tracker renders a single circle that follows the pointer over an SVG canvas. The application uses React with the `useState` hook to store the mouse position, updating the circle's `cx` and `cy` attributes on every pointer movement. The code defines a `handleMouseMove` callback that logs client coordinates, though the visible behavior is the circle's reactive tracking. The example is built with the React and ReactDOM libraries, rendering directly to an SVG element.