Made possible
by shared work.

Seasill’s licence.

Seasill is proprietary software, © 2026 Seasill, all rights reserved. It is licensed to you, not sold, under the end-user licence agreement, which is also installed with the app.

In short: Seasill covers one computer and Seasill Pro three, in any mix of Mac and Windows; Free covers one. Catalogue wallpapers are licensed for your personal use as wallpapers inside Seasill. They may not be copied out of the app or shared, and the app’s licence checks may not be worked around. The agreement itself is what applies.

Phosphene.

Seasill grew from Phosphene by kageroumado, whose way of making a real macOS wallpaper out of a video is still at the heart of Seasill on the Mac. Phosphene is used under the MIT licence, and its notice is kept here and in the app:

MIT License

Copyright (c) 2026 kageroumado

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.

Liquid glass.

The glass controls, in the app and on this site, adapt the colour-channel composition of liquid-glass-react by Max Rovensky, under the MIT licence, and follow the convex lens construction described by kube.

In the app.

Electron, Node.js and React, under the MIT licence. Chromium, under BSD-3-Clause and the licences of its components. The Lucide icons, under ISC. The Inter and JetBrains Mono typefaces, under the SIL Open Font License 1.1. yt-dlp, released into the public domain under the Unlicense.

On Windows, libmpv plays the video, under LGPL-2.1-or-later: it is linked dynamically, used unmodified, and can be replaced. Some macOS builds include FFmpeg, a GPL v3 build, run as a separate program.

The full notices are installed with the app — NOTICE.md on both platforms, and NOTICE-WINDOWS.md on Windows — and Settings › About › Licences opens them.

On this website.

This site is built with Three.js, Lenis and React, under the MIT licence, and the Lucide icons, under ISC. Its type is Inter, and in the demo JetBrains Mono, under the SIL Open Font License 1.1. The fonts are served from this site.

Wallpaper artwork.

The wallpapers in Seasill’s catalogue are licensed to you for personal use as wallpapers inside Seasill, as the licence agreement sets out; their rights remain with their owners. Videos you add yourself remain the work of their creators, and are yours to use only as far as you have the right to.