Font licences
flong bundles four coding fonts and serves them from its own domain. Each is redistributed under its own licence, reproduced here in full.
| Font | Licence | Copyright |
|---|---|---|
| JetBrains Mono | SIL OFL 1.1 | The JetBrains Mono Project Authors |
| Fira Code | SIL OFL 1.1 | The Fira Code Project Authors |
| Geist Mono | SIL OFL 1.1 | 2024 The Geist Project Authors |
| Hack | MIT | 2018 Source Foundry Authors |
Reserved font names
None of the four carries a Reserved Font Name that applies here, so each may be subset without renaming. That was part of why these four were chosen — IBM Plex Mono (“Plex”) and Source Code Pro (“Source”) are equally free but would force a rename once modified.
What this means for your exports
Rasterising text into a PNG is not font redistribution — it is an image of shapes, and no font licence governs it. The PNG path is unaffected by any of the above, whichever font you pick.
SVG export and “Copy styled” embed the actual font data. That is permitted for the four fonts here, but not necessarily for a commercial font you add yourself with Embed a font file.
flong itself
MIT licensed, © 2026 uRadical. The bundled uRadical themes are MIT, from the uRadical VS Code themes extension. Syntax highlighting is by Shiki.