MoonkaleMoonkale’s own code is MIT (LICENSE at the repository root, license = "MIT" in the workspace Cargo.toml, 2026-09-21). Anyone may use, copy, modify and redistribute it, with the copyright notice kept.
A built Moonkale is more than Moonkale. A binary, an APK or the web bundle combines the code here with third-party software, each piece under its own licence. They are all permissive (no GPL/LGPL-only code is in the tree), but “MIT” is not the whole story for a distributed artefact — their notices have to travel with it, and a few have conditions of their own:
| where | what | licence |
|---|---|---|
Rust (991 crates in Cargo.lock) | the bulk | MIT OR Apache-2.0 (≈430), MIT (136), Apache-2.0 (33) |
| bundled engines | DuckDB, LadybugDB/Kuzu | MIT |
| wasmtime + cranelift | Apache-2.0 WITH LLVM-exception | |
| Typst | Apache-2.0 | |
| tree-sitter + grammars (rust, julia, python) | MIT | |
| rustls / ring | Apache-2.0 / ISC / MIT | |
ICU4X (icu_*, zerovec, …) | Unicode-3.0 | |
webpki-roots (Mozilla’s CA bundle) | CDLA-Permissive-2.0 | |
option-ext | MPL-2.0 (file-level copyleft; unmodified use is fine) | |
| JavaScript in the app | CodeMirror, Milkdown (ProseMirror, remark), xterm.js, KaTeX | MIT |
| fonts | KaTeX fonts (editors/markdown/assets/katex/) | SIL OFL 1.1 |
| the site | Quartz | MIT |
What this means in practice: a redistributed binary should ship a THIRD-PARTY notice file (Apache-2.0 asks for the NOTICE contents, MIT/BSD for the copyright lines, OFL for the font licence). It is not generated yet — a dx bundle step for the release process (Packaging Overview).
How to list everything: cargo install cargo-license && cargo license (Rust; cargo about produces the notice file), and npx license-checker in each packages/js/* package (JavaScript). The summary above was taken from cargo metadata on 2026-09-21.