Source code and licences
The compiler that turns your LaTeX into a PDF runs inside your browser. It is pdfTeX 1.40.29 and BibTeX 0.99e from TeX Live 2026.1, compiled to WebAssembly, plus the TeX Live files they read. They are free software, and you can get, change and rebuild all of them.
TeX Live source
We build from the official TeX Live source, unchanged, at the tag texlive-2026.1:
- Browse the source at texlive-2026.1 (the TeX Live team’s mirror of their Subversion repository)
- Download it as a .tar.gz (the exact file our build script fetches)
- TeX Live’s own Subversion repository
The TeX Live files the compiler reads (classes, packages, fonts) come from the official texlive/texlive Docker image, texlive/texlive@sha256:0f4884ca7d287f47ab466d2dd405d4c901c576585363f628863a7ca7eea21301. We don’t change them: we pack them into gzip bundles so the browser can fetch only what a paper needs.
How we build it
build-wasm.sh compiles pdfTeX and BibTeX with Emscripten 5.0.7 (the official emscripten/emsdk Docker image). build-tree.sh packs the TeX Live files and builds the LaTeX format. The README says how to run them.
- README.md
- package.json
- scripts/build-fmt.ts
- scripts/build-tree.sh
- scripts/build-wasm.sh
- scripts/build-worker.mjs
- scripts/compile-node.ts
- scripts/native-reference.sh
- scripts/pack-usage.ts
- scripts/serve.mjs
- scripts/tree/export-in-container.sh
- scripts/tree/pack-tree.mjs
- scripts/tree/texlive-image.txt
- scripts/wasm/build-in-container.sh
Licences
| Part | Licence |
|---|---|
| pdfTeX | GNU GPL version 2 or later; parts from Donald Knuth’s TeX are public domain |
| xpdf code inside pdfTeX | GNU GPL |
| kpathsea (finds files for TeX) | GNU LGPL version 2.1 or later |
| BibTeX | Free software; terms in its source (texk/web2c in TeX Live) |
| zlib, libpng (used by pdfTeX) | zlib licence; libpng licence |
| TeX Live packages and fonts | Each package’s own licence: mostly the LaTeX Project Public Licence, GNU GPL, public domain, the SIL Open Font Licence and the GUST Font Licence. Look any package up in the TeX Catalogue. |
TeX Live’s copying conditions: LICENSE.TL and Copying and redistribution. TeX Live is made by volunteers from the TeX user groups; join one or support them.
These programs come with no warranty.