Open source licenses
This site runs on the open source listed below. The notices each license asks for are collected here.
Document engine: rhwp
Reading and writing HWP and HWPX documents is done by rhwp. It is MIT licensed, and the full text follows.
MIT License Copyright (c) 2025-2026 Edward Kim Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
Other open source we use
The full text of each license is at the source listed, and ships with the distributed files.
| Name | License | Source |
|---|---|---|
| pdf-lib | MIT | pdf-lib.js.org |
| pdf.js (pdfjs-dist) | Apache-2.0 | mozilla.github.io/pdf.js |
| fontkit, @pdf-lib/fontkit | MIT | github.com/foliojs/fontkit |
| PDFKit | MIT | pdfkit.org |
| qpdf-wasm | Apache-2.0 | github.com/jsscheller/qpdf-wasm |
| 7z-wasm (7-Zip, unRAR) | LGPL-2.1+ | github.com/use-strict/7z-wasm |
| libheif | LGPL-3.0 | github.com/strukturag/libheif |
| onnxruntime-web | MIT | onnxruntime.ai |
| U²-Net (u2netp) | Apache-2.0 | github.com/xuebinqin/U-2-Net |
| mammoth.js | BSD-2-Clause | github.com/mwilliamson/mammoth.js |
| SheetJS (xlsx) | Apache-2.0 | sheetjs.com |
| chardet | MIT | github.com/runk/node-chardet |
| postal-mime | MIT-0 | postal-mime.postalsys.com |
| fflate | MIT | 101arrowz.github.io/fflate |
| qrcode-generator | MIT | github.com/kazuhikoarase/qrcode-generator |
| React | MIT | react.dev |
| TanStack Router, Start | MIT | tanstack.com |
| Radix UI | MIT | radix-ui.com |
| Lucide | ISC | lucide.dev |
| three.js | MIT | threejs.org |
| @react-three/fiber, drei | MIT | github.com/pmndrs |
| Motion | MIT | motion.dev |
| Zustand | MIT | github.com/pmndrs/zustand |
| clsx | MIT | github.com/lukeed/clsx |
| tailwind-merge | MIT | github.com/dcastil/tailwind-merge |
| class-variance-authority | Apache-2.0 | cva.style |
| CSS file icons | MIT | colorswall.github.io/CSS-file-icons |
| Tailwind CSS | MIT | tailwindcss.com |
| rhwp-studio | MIT | github.com/edwardkim/rhwp |
| @noble/hashes (blake3) | MIT | github.com/paulmillr/noble-hashes |
| Noto Sans/Serif KR, Nanum, Gowun, Pretendard, D2Coding, Spoqa Han Sans, Source Han Serif K | SIL OFL 1.1 | openfontlicense.org |
| Latin Modern Math | GUST Font License | gust.org.pl |
| Tika JTD+ (Ichitaro format notes and parser rules) | Apache-2.0 | github.com/KHiyowa/Tika-JTD |
Fonts
NanumGothic, NanumMyeongjo and Noto Sans KR are embedded when a PDF needs Korean glyphs. Together with Pretendard, the interface font, all three are distributed under the SIL Open Font License 1.1.
Parts under the LGPL
7z-wasm and libheif are LGPL. To keep the replaceability the license requires, they are not bundled: they sit in versioned folders under /vendor. Swap those files and you swap the library.
Hancom’s published HWP specification
This product was developed with reference to the HWP document file (.hwp) specification published by Hancom.