Third-Party Assets and Open Source Credits
The pixel world of Speak English stands on the shoulders of many creators. The tables below list the third-party art, sound, fonts and open-source software we use, together with their licences. Anything not listed — the book text, the AI-generated illustrations and book houses, the background music — is our own.
Map and artwork
| Asset | Author | Licence | Used for |
|---|---|---|---|
| Tiny Town 1.1 | Kenney | CC0 1.0 (public domain) | Ground, roads, trees and fences on the world map |
| Roguelike / RPG pack | Kenney | CC0 1.0 | Water, roofs and pools on the world map |
| Tuxemon core buildings (core_buildings.png) | Contributors to the Tuxemon project | CC BY-SA 4.0 | Landmark buildings on the world map (centre, shops, lighthouse) |
| Kelvin Buildings (KelvinShadewing_Buildings.png) | Kelvin Shadewing | XYG Open Source License v1.1 | Some of the houses on the world map |
| Outdoor Tiles – City and Country / Objects (Zelda-like) | ArMM1998 | CC0 1.0 | Fountains, market stalls, hedge blocks |
The map image composed from CC BY-SA 4.0 assets is likewise made available under CC BY-SA 4.0, as that licence requires. Email us if you would like a copy.
Sound
| Asset | Author | Licence | Used for |
|---|---|---|---|
| Kenney Audio (Impact / Interface / UI sound packs) | Kenney | CC0 1.0 | Walking, doors, correct and incorrect reading, level-complete cues |
The three looping background tracks are synthesized by our own code. The read-aloud examples are generated with Microsoft Azure neural text-to-speech and used in this App under its terms of service.
Font
| Font | Author | Licence |
|---|---|---|
| Fusion Pixel Font 12px (proportional, zh_hans) | TakWolf | SIL Open Font License 1.1 |
Speech recognition
| Component | Author | Licence |
|---|---|---|
| sherpa-onnx (on-device streaming speech recognition framework) | k2-fsa | Apache License 2.0 |
| ONNX Runtime | Microsoft | MIT License |
| sherpa-onnx-streaming-zipformer-en-2023-06-26 (English streaming recognition model, int8) | k2-fsa | Apache License 2.0 |
All recognition happens on the device. The model is downloaded to the device from our server the first time it is used.
Full licence texts
If you are the author of any asset above and think the attribution is wrong or missing, please email mark@douwantech.com and we will correct it as soon as we can.