Standing on other people’s shoulders
OneUtil is free, and a large part of why that is possible is that around 200 open source packages did the hardest parts first. This page names the ones doing the heavy lifting, and the licences everything here is used under.
Documents
- pdf.js Apache-2.0
Mozilla’s PDF engine. Every page thumbnail and preview in the PDF toolkit is it rendering your file locally — and it is what makes verifying a redaction possible, by re-opening the finished file and checking no text survived. - pdf-lib MIT
Writes the PDFs back out: merging, splitting, rotating, stamping. - pdfmake MIT
Typesets Markdown into a real PDF with selectable text, rather than a picture of a page. - docx MIT
Builds the .docx export, with proper heading styles so Word’s navigation works. - MathJax Apache-2.0
Typesets the maths in Markdown documents. - marked MIT
Parses the Markdown behind the live preview. - DOMPurify MPL-2.0 / Apache-2.0
Sanitises rendered Markdown, so a pasted document cannot run script in your browser.
Editors and diagrams
- Monaco Editor MIT
The editor from VS Code. It is the code surface in the JSON editor and the diagram studio. - React Flow MIT
The diagram canvas — nodes, edges, panning, selection. - dagre MIT
Works out where the nodes go when you hit “arrange”. - Prism MIT
Syntax highlighting in code blocks.
Data and developer tools
- Ajv MIT
JSON Schema validation, including draft 2020-12. - sql-formatter MIT
Pretty-prints SQL across twenty dialects. - cronstrue & cron-parser MIT
Turns a cron expression into English, and works out the next run times. - js-yaml, smol-toml, fflate, jsdiff MIT / BSD-3-Clause
YAML and TOML parsing, zip creation for multi-file exports, and the diff algorithm. - qrcode & spark-md5 MIT
QR generation, and fast MD5 for large files.
Foundations
- React & Next.js MIT
The framework. OneUtil is a fully static export — there is no server behind it. - zustand & idb MIT / ISC
State management, and the IndexedDB wrapper that keeps your diagrams and bookmarks on your own machine.
Type
Set in Lato by Łukasz Dziedzic, with JetBrains Mono for code. Both are under the SIL Open Font License 1.1, and are served here with their licences alongside them: Lato · JetBrains Mono.
Data
Exchange rates in the currency converter come from Frankfurter, a free and open source rates API, which publishes the daily reference rates of the European Central Bank. It is the only network call any tool here makes.
Compatibility and trademarks
The diagram studio reads and writes Mermaid text, so diagrams move between it and any Markdown file that already renders Mermaid. That compatibility is an independent implementation of the syntax — no Mermaid code is used or bundled. Mermaid is the work and the trademark of its respective owners, and OneUtil is not affiliated with, sponsored by, or endorsed by the Mermaid project.
The full list
The complete production dependency tree, with the licence text every package ships, is at /third-party-notices.txt. It is generated from the installed tree rather than maintained by hand, so it cannot quietly go stale.
OneUtil’s own code is MIT licensed, and the source will be opened in the coming months. If you maintain something on this page: thank you. Genuinely.