Licenses and attribution
The font licences on this page are awaiting review by our lawyers.
Last updated: October 13, 2026
About this page
Read Master uses data and fonts made by other people and shared under open licences. This page gives them credit and says which licence each one is under.
Arabic dictionary definitions
The short Arabic definitions in Arabic vocabulary questions come from Arabic WordNet 4.0 by Salah Abdo (DOI 10.5281/zenodo.18759165), used under the Creative Commons Attribution 4.0 International licence (CC BY 4.0). Arabic WordNet 4.0 is an AI-assisted translation of Open English WordNet 2024, which is based on Princeton WordNet 3.0.
Changes we made: we keep one definition for each word, and only for words that are also in our Arabic word-frequency list.
Word lists
| What it is | Source | Licence |
|---|---|---|
| How common each English word is (the 50,000 most common words) | SUBTLEX-US, through the subtlex-word-frequencies package | ISC |
| How common each Arabic word is | FrequencyWords by Hermit Dave, built from OpenSubtitles 2016 | MIT |
| Very common words to skip (English and Arabic) | The stopword package | MIT |
Fonts
Every font in this table is under the SIL Open Font License, version 1.1.
| Font | Where you see it | Copyright |
|---|---|---|
| Atkinson Hyperlegible | Optional easier-reading font in the reader | © 2020 Braille Institute of America, Inc. |
| OpenDyslexic | Optional dyslexia font in the reader | © 2019 Abbie Gonzalez |
| Literata | Book text and headings | © 2017 The Literata Project Authors |
| Instrument Sans | Menus, buttons and other interface text | © 2022 The Instrument Sans Project Authors |
| Fragment Mono | Small labels | © 2022 The Fragment-Mono Project Authors |
Open-source software
Read Master is also built with open-source software. Write to us at the address below for the full list and its licences.
Questions
If you made something listed here and the credit is wrong or missing, write to [email protected] and we will fix it.