GSAP

Reach for GSAP when the brief needs a sequenced timeline, scroll-position-driven scrubbing (ScrollTrigger), or SVG path morphing — Framer Motion and CSS transitions cover component enter/exit far more cleanly and should stay the default for React UI state. In React always install `@gsap/react` and wrap animations in `useGSAP()`; a bare `useEffect` leaks tweens across Strict Mode double-renders and hot reloads. Every plugin needs an explicit `gsap.registerPlugin(...)` call and tree-shakes out silently if you forget, and note the licence is source-available proprietary, not MIT — fine to ship, not fine to vendor into an animation-editor product.

Why it is here. GSAP is the twenty-year reference implementation of web animation, and Webflow making the paid plugin set free removed the one reason teams reached for weaker alternatives. Its docs are published as `.md` alongside a full llms.txt index, which makes it one of the few motion libraries an agent can actually read end to end.