CapMux — Third-Party Notices
CapMux (© 2026 CapMux, proprietary; see LICENSE.md) is built on open-source software, fonts
and models. They are licensed to you by their authors under the licences below, not under CapMux's
licence, and nothing in LICENSE.md limits your rights under them. Where a licence asks for its text
to travel with the software, it is included in the app as noted (Electron/Chromium licence files,
runtime/python/.../LICENSE.txt and each package's *.dist-info folder, ffmpeg-LICENSE.txt next
to ffmpeg, each font's OFL.txt).
Status: compiled for CapMux 1.16.0 from the build scripts, the packaged runtimes and the package metadata (PyPI / Hugging Face). Items marked [unverified] could not be confirmed and should be checked by the owner.
1. Shipped in the app (macOS arm64 and Windows x64)
Electron, Chromium, Node.js
| Component | Licence | Source |
|---|---|---|
| Electron 45 (app shell) | MIT | https://github.com/electron/electron |
| Chromium (inside Electron) | BSD-3-Clause and the many licences listed in LICENSES.chromium.html |
https://www.chromium.org/ |
| Node.js (inside Electron) | MIT and others (listed in LICENSES.chromium.html) |
https://github.com/nodejs/node |
Electron's LICENSE ships as LICENSE.electron.txt and Chromium's notices as
LICENSES.chromium.html (Windows: next to CapMux.exe; macOS: CapMux.app/Contents/Resources/).
CapMux's Electron code has no other Node.js runtime dependencies; electron-builder (MIT,
https://github.com/electron-userland/electron-builder) is a build tool and is not shipped.
Python runtime
| Component | Licence | Source |
|---|---|---|
| CPython 3.13 | PSF License 2.0 (text: runtime/python/lib/python3.13/LICENSE.txt, Windows runtime/python/LICENSE.txt) |
https://www.python.org/ |
| python-build-standalone (relocatable build of CPython) | MPL-2.0 (build system); the libraries it builds in keep their own licences, among them OpenSSL (Apache-2.0), SQLite (public domain), libffi (MIT), zlib (Zlib), bzip2 (bzip2 licence), XZ (0BSD), mpdecimal (BSD-2-Clause), expat (MIT) and Tcl/Tk (Tcl/Tk licence) | https://github.com/astral-sh/python-build-standalone |
Microsoft Visual C++ runtime DLLs (Windows only: msvcp140*.dll, vcruntime140*.dll, concrt140.dll, vcomp140.dll) |
Microsoft Visual C++ Redistributable licence terms [unverified: redistribution rights come from the Visual Studio licence of the build machine; the owner should confirm] | https://learn.microsoft.com/cpp/windows/latest-supported-vc-redist |
Python packages in the runtime
Licences as declared in each package's metadata; full texts are in the package's *.dist-info
folder inside the app.
Fonts
All bundled caption fonts are under the SIL Open Font License 1.1 (https://openfontlicense.org);
each family's OFL.txt with its copyright line ships next to the font files in
capmux/static/fonts/<family>/. The OFL lets the fonts be bundled with software that is sold, and its
terms do not apply to documents or videos made with the fonts, so captions you export are not
affected. The fonts are not sold on their own.
| Family | Copyright (from its OFL.txt) |
Reserved Font Name | Source |
|---|---|---|---|
| Caveat | 2014 The Caveat Project Authors | — | https://github.com/googlefonts/caveat |
| Comfortaa | 2011 The Comfortaa Project Authors | "Comfortaa" (file unmodified) | https://github.com/alexeiva/comfortaa |
| Dela Gothic One | 2020 The Dela Gothic Project Authors | — | https://github.com/syakuzen/DelaGothic |
| Exo 2 | 2013 The Exo 2 Project Authors | — | https://github.com/googlefonts/Exo-2.0 |
| Golos Text | 2019 The Golos Text Project Authors | — | https://github.com/googlefonts/golos-text |
| Inter | 2020 The Inter Project Authors | — | https://github.com/rsms/inter |
| Lobster | 2010 The Lobster Project Authors | "Lobster" (file unmodified) | https://github.com/impallari/The-Lobster-Font |
| Manrope | 2018 The Manrope Project Authors | — | https://github.com/googlefonts/manrope |
| Montserrat | 2024 The Montserrat.Git Project Authors | — | https://github.com/JulietaUla/Montserrat |
| Nunito | 2014 The Nunito Project Authors | — | https://github.com/googlefonts/nunito |
| Oswald | 2016 The Oswald Project Authors | — | https://github.com/googlefonts/OswaldFont |
| Rubik | 2015 The Rubik Project Authors | — | https://github.com/googlefonts/rubik |
| Russo One | 2011-2012 Jovanny Lemonad | "Russo" (file unmodified) | https://fonts.google.com/specimen/Russo+One |
| Unbounded | 2022 The Unbounded Project Authors | — | https://github.com/googlefonts/unbounded |
Dela Gothic One is a subset of the original font (only the glyphs CapMux needs, about 120 KB instead of 2.5 MB). The OFL allows modified versions under the same licence; because Dela Gothic One declares no Reserved Font Name, the subset may keep its name. It remains under the OFL. The fonts with a Reserved Font Name (Comfortaa, Lobster, Russo One) are byte-identical to the Google Fonts releases.
2. FFmpeg (GPL) — ffmpeg and ffprobe programs, and the FFmpeg libraries in PyAV
ffmpeg / ffprobe programs
CapMux ships static builds of the ffmpeg and ffprobe command-line programs of FFmpeg 9.0.2
(runtime/bin/). These builds were not made by CapMux; they are used unmodified:
- macOS arm64: Martin Riedl's static release build 9.0.2,
https://ffmpeg.martin-riedl.de/download/macos/arm64/1789931890_9.0.2/ (library versions in
versions.txtthere; build scripts: https://git.martin-riedl.de/ffmpeg/build-script). Configured with--enable-gpl --enable-version3and, among others, libx264 and libx265. - Windows x64: Gyan Doshi's "essentials" release build 9.0.2,
https://www.gyan.dev/ffmpeg/builds/ and
https://github.com/GyanD/codexffmpeg/releases/tag/9.0.2 (
ffmpeg-9.0.2-essentials_build.7z; itsREADME.txtlists the included libraries and versions). Configured with--enable-gpl --enable-version3, among others libx264, libx265 and libxvid.
Because these builds include GPL components (for example x264 and x265, GPL-2.0-or-later) and are
configured as GPL version 3, the ffmpeg and ffprobe binaries are licensed under the GNU General
Public License version 3 (text: runtime/bin/ffmpeg-LICENSE.txt, also
https://www.gnu.org/licenses/gpl-3.0.html). FFmpeg's own source code is at https://ffmpeg.org/
(release tarball: https://ffmpeg.org/releases/ffmpeg-9.0.2.tar.xz).
CapMux runs ffmpeg and ffprobe as separate programs (it starts them as processes and exchanges files and data with them); it does not link them into its own code. The GPL therefore applies to these two programs, not to CapMux, which is shipped alongside them as a separate work ("aggregate"). You may use, copy, modify and redistribute ffmpeg and ffprobe under the GPL, and you may replace them with your own build in the same location.
FFmpeg libraries and codecs inside PyAV, and libsndfile
The PyAV (av) package in the runtime bundles shared FFmpeg libraries (libavcodec, libavformat,
libavfilter, libavutil, libswscale, libswresample, libavdevice; built with --enable-version3, which
they report as "LGPL version 3 or later") together with codec libraries, among them x264 and
x265 (GPL-2.0-or-later), LAME (LGPL), twolame (LGPL), opencore-amr (Apache-2.0), libvpx and libaom
(BSD), dav1d (BSD), SVT-AV1 (BSD-3-Clause-Clear), OpenH264 (BSD-2-Clause), Opus, Vorbis, Ogg and Speex
(BSD), WebP (BSD), GMP (LGPL-3.0-or-later or GPL-2.0-or-later) and, on Windows, the MinGW/GCC runtime
(GCC Runtime Library Exception), libiconv (LGPL) and zlib (Zlib). They are in av/.dylibs/ (macOS) or
av.libs/ (Windows). The source of each is available from its project; PyAV's binary build recipe is
at https://github.com/PyAV-Org/pyav-ffmpeg. [unverified: the licence of this combination as a
whole; the FFmpeg libraries report LGPL-3.0-or-later, but the wheel also contains the GPL x264 and
x265 libraries, so these notices treat it as containing GPL code.]
soundfile bundles libsndfile (LGPL-2.1-or-later). LGPL libraries in CapMux are separate shared library files: you may replace them with modified versions, and reverse engineering for debugging such modifications is permitted.
Source code offer
For at least three years after the last time a CapMux version was distributed, the CapMux owner will give anyone who asks a copy of the complete corresponding source code of the GPL- and LGPL-licensed components shipped with that version (the ffmpeg and ffprobe binaries and the libraries listed above, including the scripts used to build them as far as their builders publish them), on a medium customarily used for software interchange or as a download, for no more than the cost of providing it. Ask at support@capmux.app, naming the CapMux version and platform. The same sources are publicly available from the upstream projects and build pages linked above.
H.264 and H.265 encoding may be subject to patent licences in some countries; none is granted by CapMux or by these licences.
3. Downloaded by the app on first use (not shipped in the download)
Speech engine
On the first transcription CapMux downloads these exact Python wheels from the Python Package Index (and, on Windows with an NVIDIA GPU, PyTorch's CUDA build from https://download.pytorch.org/) into its own data folder. They come straight from their publishers under their own licences:
| Package | Platform | Licence | Source |
|---|---|---|---|
| mlx, mlx-metal | macOS | MIT | https://github.com/ml-explore/mlx |
| mlx-whisper | macOS | MIT | https://github.com/ml-explore/mlx-examples |
| faster-whisper | Windows | MIT | https://github.com/SYSTRAN/faster-whisper |
| ctranslate2 | Windows | MIT | https://github.com/OpenNMT/CTranslate2 |
| torch (PyTorch) | both | BSD-3-Clause style (Apache-2.0 AND Apache-2.0 WITH LLVM-exception AND BSD-2-Clause AND BSD-3-Clause AND BSL-1.0 AND MIT) | https://github.com/pytorch/pytorch |
| torch CUDA build (cu126) | Windows, optional | as torch; includes NVIDIA CUDA runtime, cuBLAS and cuDNN libraries under NVIDIA's licence terms | https://pytorch.org/, https://docs.nvidia.com/cuda/eula/ |
| transformers, tokenizers, safetensors | both | Apache-2.0 | https://github.com/huggingface |
| sherpa-onnx, sherpa-onnx-core | both | Apache-2.0 | https://github.com/k2-fsa/sherpa-onnx |
| onnxruntime | both | MIT | https://github.com/microsoft/onnxruntime |
| protobuf | both | BSD-3-Clause | https://github.com/protocolbuffers/protobuf |
| flatbuffers | both | Apache-2.0 | https://github.com/google/flatbuffers |
| numba | macOS | BSD-2-Clause | https://github.com/numba/numba |
| llvmlite | macOS | BSD-2-Clause AND Apache-2.0 WITH LLVM-exception | https://github.com/numba/llvmlite |
| scipy | macOS | BSD-3-Clause (and bundled licences) | https://github.com/scipy/scipy |
| tiktoken | macOS | MIT | https://github.com/openai/tiktoken |
| sympy, mpmath, networkx | both | BSD-3-Clause | https://github.com/sympy/sympy, https://github.com/mpmath/mpmath, https://github.com/networkx/networkx |
| regex | both | Apache-2.0 AND CNRI-Python | https://github.com/mrabarnett/mrab-regex |
| requests | both | Apache-2.0 | https://github.com/psf/requests |
| urllib3, charset-normalizer | both | MIT | https://github.com/urllib3/urllib3, https://github.com/jawah/charset_normalizer |
| Jinja2, MarkupSafe | both | BSD-3-Clause | https://github.com/pallets |
| Pygments | both | BSD-2-Clause | https://github.com/pygments/pygments |
| rich, typer, markdown-it-py, mdurl, more-itertools, setuptools | both | MIT | PyPI project pages |
| shellingham | both | ISC | https://github.com/sarugaku/shellingham |
(The exact set and versions are pinned per build in capmux/speech-lock.json.)
Speech models (Hugging Face)
Downloaded from https://huggingface.co/ into the Hugging Face cache when first needed. None of them is CC-BY; the MIT and Apache-2.0 licences ask for their notice when the model is redistributed, which CapMux does not do (you download each model from its repository).
Whisper (speech recognition) — OpenAI Whisper, MIT, © 2022 OpenAI (https://github.com/openai/whisper). CapMux uses these conversions:
| Model | Platform | Licence | Repository |
|---|---|---|---|
| turbo | macOS | MIT (Whisper) [unverified: the conversion's card states no licence] | https://huggingface.co/mlx-community/whisper-large-v3-turbo |
| large-v3 | macOS | MIT | https://huggingface.co/mlx-community/whisper-large-v3-mlx |
| medium | macOS | MIT (Whisper) [unverified: the conversion's card states no licence] | https://huggingface.co/mlx-community/whisper-medium-mlx |
| small | macOS | MIT (Whisper) [unverified: the conversion's card states no licence] | https://huggingface.co/mlx-community/whisper-small-mlx |
| turbo | Windows | MIT | https://huggingface.co/deepdml/faster-whisper-large-v3-turbo-ct2 |
| large-v3 | Windows | MIT | https://huggingface.co/Systran/faster-whisper-large-v3 |
| medium | Windows | MIT | https://huggingface.co/Systran/faster-whisper-medium |
| small | Windows | MIT | https://huggingface.co/Systran/faster-whisper-small |
Word alignment (wav2vec2, one per language; licence from each model card):
Speaker detection (sherpa-onnx ONNX exports by k2-fsa):
| Model | Repository | Licence |
|---|---|---|
| pyannote segmentation-3.0 | https://huggingface.co/csukuangfj/sherpa-onnx-pyannote-segmentation-3-0, converted from https://huggingface.co/pyannote/segmentation-3.0 | MIT (pyannote model card; the conversion's card states none) |
NVIDIA TitaNet-S speaker embedding (nemo_en_titanet_small.onnx) |
https://huggingface.co/csukuangfj/speaker-embedding-models, from https://catalog.ngc.nvidia.com/orgs/nvidia/teams/nemo/models/titanet_small | Apache-2.0 (NGC card: covered by the NeMo Toolkit licence, which is Apache-2.0; the conversion's card states none) |
4. The website (capmux.app)
Counterscale
The page-view counter of capmux.app (its tracker script at https://capmux.app/stats/tracker.js and the
owner's dashboard) is Counterscale 3.4.1, https://github.com/benvinegar/counterscale, MIT licence:
Copyright 2025 Ben Vinegar
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.