The library that taught a generation of pages to bounce, and still the fastest way to say "this entered" without writing a keyframe. Version 4 made it well-behaved: a namespaced animate__ prefix so it cannot collide, custom properties instead of hand-edited durations, and a real prefers-reduced-motion rule rather than a note in the README. Licensed under the Hippocratic License, which is worth knowing before it goes into a corporate build.
This site does not use it. Nuxt UI's own keyframes (fade-in, scale-in, slide-in-from-top-and-fade, reached as animate-[name_200ms_ease-out]) cover entrances, and the Delight principle's celebrate() and the view transitions cover the rest. tw-animate-css, the same idea as Tailwind utilities, was installed and never imported; it was removed rather than wired up, because its accordion-* and collapsible-* keyframes replace Nuxt UI's app-wide. Where Animate.css still wins is a prototype or a slide: one stylesheet, two classes, done.