---
title: "Credits and licences (motion)"
description: "The motion principles in this skill (frequency-of-use gate, ease-out for UI, no scale(0), origin-aware popovers, transitions vs keyframes, press feedback…"
canonical: https://void-design.vercel.app/docs/motion/CREDITS
lastModified: 2026-09-16
---

# Credits and licences

## Emil Kowalski

The motion principles in this skill (frequency-of-use gate, ease-out for UI, no `scale(0)`, origin-aware popovers, transitions vs keyframes, press feedback, instant subsequent tooltips, exit faster than enter, reduced motion as "fewer and gentler") follow Emil Kowalski's work. They are written here in void's own words, with void tokens and measurements.

Further reading (not copied; read the originals):
- Course: [Animations on the Web](https://animations.dev)
- [7 Practical Animation Tips](https://emilkowal.ski/ui/7-practical-animation-tips)
- [Great Animations](https://emilkowal.ski/ui/great-animations)
- [Good vs Great Animations](https://emilkowal.ski/ui/good-vs-great-animations)
- [You Don't Need Animations](https://emilkowal.ski/ui/you-dont-need-animations)
- [Agents with Taste](https://emilkowal.ski/ui/agents-with-taste)
- [Building a Toast Component](https://emilkowal.ski/ui/building-a-toast-component) (Sonner)
- [Building a Drawer Component](https://emilkowal.ski/ui/building-a-drawer-component) (Vaul)
- [The Magic of Clip Path](https://emilkowal.ski/ui/the-magic-of-clip-path)

Portions of `recipes.md` marked † (press, popover, tooltip, modal, drawer, toast mount, stagger, hold-to-confirm, tab clip-path, blur crossfade) and the easing/duration tables in `timing.md` are adapted from [emilkowalski/skills](https://github.com/emilkowalski/skills) (`skills/animate/RECIPES.md`, `skills/review-animations/STANDARDS.md`), modified to use void tokens, Radix/Base UI/native variants and void's reduced-motion rules. That repository is licensed as follows:

```
MIT License

Copyright (c) 2026 Emil Kowalski

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
```

No content from the paid courses (animations.dev, aiforui.dev) is used.

## Measurements

Durations, easing frequencies and site behaviour come from void's own teardown of 24 sites (headless Chromium 149, 2026-09-15) and the owner's shipped apps.

## Other

- Radix Colors lightness recipe (via `packages/tokens/scripts/generate.ts`): https://www.radix-ui.com/colors
- Motion bundle measurements (LazyMotion +32 KB, motion +46 KB): void performance research, Next 16.3.5 production build.