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Open-source notices

We build on open-source software and are grateful to the people who make it. Each part is covered only by its own licence, and nothing in our terms limits the rights those licences give you.

Velocity download manager

This is the notices file the installer puts next to Velocity (THIRD-PARTY-NOTICES.txt), word for word. The full licence texts are installed in Velocity's licenses folder.

VELOCITY BY ZEMARIS - THIRD-PARTY NOTICES
Download Manager for Windows

Velocity is built with open-source software. We are grateful to the people who make it.
This file lists each part, its licence, and where to get its source code. The full licence
texts are in the "licenses" folder next to this file (and aria2's in the "bin" folder).
Each part is covered only by its own licence. The Velocity licence agreement (EULA.txt)
does not limit any right these licences give you.

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1. aria2 (torrent and multi-source engine)
   File:     bin\aria2c.exe - a separate program that Velocity starts when needed.
   Version:  1.37.0 (official Windows build from the aria2 project)
   Licence:  GNU General Public License, version 2 or later (GPL-2.0-or-later), with an
             extra permission to link with OpenSSL.
   Texts:    bin\aria2-COPYING.txt (the GPL), bin\aria2-LICENSE.OpenSSL.txt,
             bin\aria2-README.html (lists the libraries the build may contain).
   Source:   https://github.com/aria2/aria2/releases/tag/release-1.37.0
   Copyright (C) 2006, 2019 Tatsuhiro Tsujikawa and contributors.

   Written offer for the source code: for at least three years from the date we last
   ship this version of aria2, anyone who received it from us may ask for the complete
   source code of the exact aria2 version we ship. Email admin@zemaris.com and we will send
   it (as a download link, or on a physical medium for no more than the cost of making and
   sending it). We have not changed aria2: the code we ship is the aria2 project's own
   release.

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2. Python (the language Velocity is written in)
   Velocity includes the Python runtime and its standard library.
   Licence:  Python Software Foundation License, version 2 (PSF-2.0).
   Text:     licenses\Python-<version>-LICENSE.txt
   Source:   https://www.python.org/downloads/source/
   Copyright (c) 2001 Python Software Foundation. All rights reserved.

   Python includes other libraries under their own licences. Among them: OpenSSL
   (Apache License 2.0), Expat (MIT), libffi (MIT), zlib (zlib licence), libmpdec
   (BSD-2-Clause), mimalloc (MIT), Zstandard (BSD-3-Clause), bzip2 (BSD-style), XZ Utils
   (public domain / 0BSD), SQLite (public domain) and Tcl/Tk (BSD-style, used for the
   "choose a folder" box). Their licence texts are in:
             licenses\Python-<version>-LICENSE.txt
             licenses\Python-included-software.txt
             licenses\Tcl-Tk-license.terms.txt

   It also contains Microsoft Visual C++ runtime files (Microsoft Distributable Code),
   used under Microsoft's terms for redistribution. Microsoft is not involved with and
   does not endorse Velocity.

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3. yt-dlp (video engine)
   Licence:  The Unlicense (public domain dedication).
   Text:     licenses\yt-dlp-<version>\LICENSE
   Source:   https://github.com/yt-dlp/yt-dlp
   Velocity may update its video engine to a newer yt-dlp release by itself. Newer
   releases come from the yt-dlp project under the same licence.

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4. certifi (list of trusted website certificates, used by the video engine)
   Licence:  Mozilla Public License 2.0 (MPL-2.0).
   Text:     licenses\certifi-<version>\LICENSE
   Source:   https://github.com/certifi/python-certifi (the files are unchanged)

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5. PyInstaller (packs Velocity into Velocity.exe)
   The small start-up program inside Velocity.exe (the "bootloader") comes from PyInstaller.
   Licence:  GNU General Public License, version 2 or later, with the PyInstaller bootloader
             exception, which allows it to be used in programs under any licence.
   Text:     licenses\pyinstaller-<version>\COPYING.txt
   Source:   https://github.com/pyinstaller/pyinstaller

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6. FFmpeg (optional, for MP3 audio and HD video)
   FFmpeg is NOT part of Velocity and is not shipped in this installer. If you tick the
   FFmpeg box during setup, Setup asks the Windows package manager (winget) to install the
   separate "FFmpeg Essentials" build, which comes from its own publisher. Velocity then
   starts it as a separate program when it needs it.
   Licence:  FFmpeg is licensed under the GNU LGPL 2.1 or later; the Essentials build
             includes GPL parts, so that build is under the GNU GPL version 3.
   Source:   https://ffmpeg.org/download.html and https://www.gyan.dev/ffmpeg/builds/
   FFmpeg is a trademark of Fabrice Bellard, originator of the FFmpeg project.

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7. Inno Setup (makes the Velocity installer and uninstaller)
   Copyright (C) 1997-2026 Jordan Russell. Portions Copyright (C) 2000-2026 Martijn Laan.
   Licence:  Inno Setup License (free to use, also for commercial programs).
   Source:   https://jrsoftware.org/isinfo.php

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Everything else in Velocity (the app, its windows, the browser extension and the
icons) is Copyright (C) 2026 Zemaris. All rights reserved.

Questions, or a request for source code: admin@zemaris.com

Velocity PDF

Velocity PDF is not released yet. Its full notices file will be published here and installed with it. It is built with these open-source parts, among others:

Velocity PDF also uses Microsoft Edge WebView2, which is part of Windows and covered by Microsoft's own terms.

Questions, or a request for source code under a licence that offers it: admin@zemaris.com.