Silent Syllable
Licences
Silent Syllable is built on work other people gave away. This page says what that work is, what each piece is licensed under, and which parts of the app are our own.
What this app is built on
These ship to your browser as part of the app. Each link goes to the licence text as the project publishes it.
- Next.js — MIT. Licence text. Copyright Vercel, Inc.
- React and React DOM — MIT. Licence text. Copyright Meta Platforms, Inc. and affiliates.
- MediaPipe Tasks Vision (
@mediapipe/tasks-vision) — Apache License 2.0. Licence text. Copyright Google LLC. This is the hand tracker; see below. - Vercel Web Analytics (
@vercel/analytics) — MIT. Licence text. Copyright Vercel, Inc. - Tailwind CSS — MIT. Licence text. Copyright Tailwind Labs, Inc. Tailwind runs at build time; what reaches you is plain CSS.
Tools used to build and check it
None of these are sent to your browser, but they shaped what you are using, so they are worth naming.
- TypeScript — Apache License 2.0. Licence text. Copyright Microsoft Corporation.
- ESLint — MIT. Licence text.
- Playwright — Apache License 2.0. Licence text. Copyright Microsoft Corporation.
- axe-core — Mozilla Public License 2.0. Licence text. Copyright Deque Systems, Inc. Every screen is checked against it.
- html-validate — MIT. Licence text.
The hand tracker and its model
Nothing is fetched from a content delivery network, so the MediaPipe runtime and the model it loads are copied into the app itself and served from it. That is what makes practice work offline, and it is why they are listed here as things we distribute rather than things we merely depend on.
- The WebAssembly runtime in
public/mediapipe/wasm/is the build published in@mediapipe/tasks-vision, unchanged, and carries the same Apache License 2.0. Copyright Google LLC. - The hand landmarker model —
hand_landmarker.task— is Google's published model bundle, containing a palm detector and a hand landmark model. It is released as part of MediaPipe Solutions under the same Apache License 2.0. Google ships no separate licence file alongside the model bundle; what it does publish is a model card describing how it was trained and tested. We did not train it and have not altered it.
Fonts
Both are open fonts, served by the app rather than loaded from Google's servers, so nothing about your visit is disclosed to a font host.
- Inter, used for reading text — SIL Open Font License 1.1. Licence text. Copyright The Inter Project Authors.
- Poppins, used for headings and large numerals — SIL Open Font License 1.1. Licence text. Copyright The Poppins Project Authors.
What is ours
Every icon, badge and illustration in the app was drawn for it — including Clip, the paper pin — and none of it is traced from or derived from anyone else's artwork. The cartoon hand you see demonstrating each shape is drawn from scratch in code, as is the logic that decides whether your hand matches a sign.
The written text — the wording on every screen, the practice instructions, the badge names — was written for this app.
A note about the signs themselves
American Sign Language is a language. Nobody owns it, and we make no claim over it. The letters, numbers and words taught here belong to the Deaf community that built the language and keeps it alive, and you are free to use them, teach them and pass them on without asking anyone.
What is ours is only the wording: the short descriptions of how to make each shape — where the thumb sits, which fingers fold — were written for this app. Anyone is free to describe the same signs in their own words.
Corrections
If something on this page is wrong, or a licence is missing, we would rather know than be polite about it. The page will be corrected.