- Qt 6.6
- Licenses Used in Qt
- Qt 6.6.3 Reference Documentation

# Licenses Used in Qt

Qt contains some code that is not provided under the GNU Lesser General Public License (LGPL) or the Qt Commercial License, but rather under specific licenses from the original authors.

The Qt Company gratefully acknowledges these and other contributions to Qt. We recommend that programs that use Qt also acknowledge these contributions, and quote these license statements in an appendix to the documentation.

Note: You only need to comply with (and acknowledge) the licenses of the third-party components that you are using with your application. Click the name of the component to see the licensing details.

Third-party Licenses

The following table lists parts (modules) of Qt 6.6.3 that incorporate code licensed under third-party open-source licenses:

## Qt 3D

Dear ImGui - ProggyClean.ttf | MIT License
Dear ImGui - stb | MIT License or Public Domain
Dear ImGui, version v1.66b | MIT License

## Qt 5 Core Compatibility APIs

Text Codec: EUC-JP | BSD 2-clause "Simplified" License
Text Codec: EUC-KR | BSD 2-clause "Simplified" License
Text Codec: GBK | BSD 2-clause "Simplified" License
Text Codec: ISO 2022-JP (JIS) | BSD 2-clause "Simplified" License
Text Codec: Shift-JIS | BSD 2-clause "Simplified" License
Text Codec: TSCII | BSD 2-clause "Simplified" License
Text Codecs: Big5, Big5-HKSCS | BSD 2-clause "Simplified" License

## Qt Bluetooth

BlueZ | GNU General Public License v2.0 only (This does not force user code to be GPL'ed. For more info see details.)

## Qt Core

BLAKE2 (reference implementation), version 54f4faa4c16ea34bcd59d16e8da46a64b259fc07 | Creative Commons Zero v1.0 Universal or Apache License 2.0
Data Compression Library (zlib), version 1.3.1 | Zlib License
Easing Equations by Robert Penner | BSD 3-clause "New" or "Revised" License
Efficient Binary-Decimal and Decimal-Binary Conversion Routines for IEEE Doubles, version 3.3.0 | BSD 3-clause "New" or "Revised" License
KWin, version 5.13.4 | BSD-3-Clause
KWin, version 5.13.4 | BSD-3-Clause
KWin, version 5.13.4 | BSD-3-Clause
KWin, version 5.13.4 | BSD-3-Clause
MD4 | Public Domain
MD5 | Public Domain
PCRE2 - Stack-less Just-In-Time Compiler, version 10.43 | BSD 2-clause "Simplified" License
PCRE2, version 10.43 | BSD 3-clause "New" or "Revised" License with PCRE2 binary-like Packages Exception
QEventDispatcher on macOS | BSD 3-clause "New" or "Revised" License
Secure Hash Algorithm SHA-1 | Public Domain
Secure Hash Algorithm SHA-3 - Keccak, version 3.2 | Creative Commons Zero v1.0 Universal
Secure Hash Algorithm SHA-3 - brg_endian, version https://github.com/BrianGladman/sha/ commit 4b9e13ead2c5b5e41ca27c65de4dd69ae0bac228 | BSD 2-clause "Simplified" License
Secure Hash Algorithms SHA-384 and SHA-512 | BSD 3-clause "New" or "Revised" License
SipHash Algorithm | Creative Commons Zero v1.0 Universal
TinyCBOR, version 0.6.0 | MIT License
Unicode Character Database (UCD), version 30 | Unicode License Agreement - Data Files and Software (2016)
Unicode Common Locale Data Repository (CLDR), version v44.1 | Unicode License V3
extra-cmake-modules, version 5.84.0 | BSD-3-Clause
extra-cmake-modules, version 5.84.0 | BSD-3-Clause
extra-cmake-modules, version 5.84.0 | BSD-3-Clause
forkfd | MIT License

## Qt D-Bus

libdus-1 headers, version dbus-1.13.12 | Academic Free License v2.1, or GNU General Public License v2.0 or later

## Qt GRPC

gRPC, version 1.50.1 | Apache License 2.0

## Qt GUI

Adobe Glyph List For New Fonts, version 1.7 | BSD 3-Clause "New" or "Revised" License
Anti-aliasing rasterizer from FreeType 2 | Freetype Project License or GNU General Public License v2.0 only
Bitstream Vera Font, version 1.10 | Bitstream Vera Font License
Cocoa Platform Plugin | BSD 3-clause "New" or "Revised" License
D3D12 Memory Allocator, version f128d39b7a95b4235bd228d231646278dc6c24b2 | MIT License
DejaVu Fonts, version 2.37 | Bitstream Vera Font License
Freetype 2 - Bitmap Distribution Format (BDF) support | MIT License
Freetype 2 - Portable Compiled Format (PCF) support | MIT License and MIT Open Group variant
Freetype 2 - zlib | Zlib License
Freetype 2, version 2.13.2 | Freetype Project License or GNU General Public License v2.0 only
HarfBuzz-NG, version 8.3.0 | MIT License
IAccessible2 IDL Specification, version 1.3.0 | BSD 3-clause "New" or "Revised" License
LibJPEG-turbo, version 3.0.2 | Independent JPEG Group License and BSD 3-Clause "New" or "Revised" License and zlib License
LibPNG, version 1.6.43 | Libpng License and PNG Reference Library version 2
MD4C, version 0.5.2 | MIT License
Mipmap generator for D3D12, version 0aa79bad78992da0b6a8279ddb9002c1753cb849 | MIT License
Native Style for Android | Apache License 2.0
OpenGL ES 2 Headers, version Revision 27673 | MIT License
OpenGL Headers, version Revision 27684 | MIT License
Pixman, version 0.17.12 | MIT License
Smooth Scaling Algorithm | BSD 2-clause "Simplified" License and Imlib2 License
Vulkan API Registry, version 1.3.223 | Apache License 2.0 or MIT License
Vulkan Memory Allocator, version 3.0.1 | MIT License
WebGradients | MIT License
Wintab API | LCS-Telegraphics License
X Server helper | X11 License and Historical Permission Notice and Disclaimer
XCB-XInput | MIT License
sRGB color profile icc file | International Color Consortium License

## Qt Image Formats

TIFF Software Distribution (libtiff), version 4.6.0 | Libtiff License
WebP (libwebp), version 1.3.2 | BSD 3-clause "New" or "Revised" License

## Qt Multimedia

FFmpeg, version n6.1.1 | GNU Lesser General Public License v2.1 or later and BSD 3-Clause "New" or "Revised" License and BSD 2-Clause "Simplified" License and BSD Source Code Attribution and ISC License and MIT License and Mozilla Public License 2.0
boost | Boost Software License 1.0
libjpeg | Independent JPEG Group License
zlib | Zlib License

## Qt Network

The Public Suffix List, version 883ced078a83f9d79a98933145425c221a5e51f0, fetched on 2024-01-25 | Mozilla Public License 2.0
libpsl - C library to handle the Public Suffix List, version 664f3dc85259ec65e30248a61fa1c45b7b0e4c3f | BSD 3-clause "New" or "Revised" License

## Qt OPC UA

Open62541, version 1.3.6 | Mozilla Public License 2.0 and Creative Commons Zero v1.0 Universal and Creative Commons Attribution Share Alike 4.0 International and BSD 3-Clause "New" or "Revised" License and Apache License 2.0 and MIT License

## Qt PDF

Abseil | Apache 2.0
FreeType | Custom license "inspired by the BSD, Artistic, and IJG (Independent
PDFium | BSD
The Chromium Project | BSD 3-clause "New" or "Revised" License
harfbuzz-ng | MIT
icu | MIT
libjpeg-turbo | Custom license
libpng | Libpng license
zlib | Custom license

## Qt Positioning

Clip2Tri Polygon Triangulation Library | MIT License
Clipper Polygon Clipping Library, version 6.4.2 | Boost Software License 1.0
Poly2Tri Polygon Triangulation Library | BSD 3-clause "New" or "Revised" License

## Qt QML

JavaScriptCore Macro Assembler | BSD 2-clause "Simplified" License

## Qt Quick 3D

Godot Engine: Fog | MIT License
Godot Engine: ProceduralSky | MIT License
Intel Embree, version 3.13.3 | Apache License 2.0
Open Asset Import Library, version 5.2.5 | BSD 3-clause "New" or "Revised" Licensee
Tiny OpenEXR, version v1.0.8 | BSD 3-clause "New" or "Revised" License
meshoptimizer, version v0.18 | MIT License
xatlas, version 16ace528acd2cf1f16a7c0dde99c42c486488dbe | MIT License

## Qt Quick 3D Physics

NVIDIA PhysX SDK, version PhysX_4.1.2.29882248 | BSD 3-Clause "New" or "Revised" License

## Qt Quick Controls

Shadow values from Angular Material | MIT License

## Qt SQL

SQLite, version 3.45.2 | Public Domain

## Qt SVG

XSVG | Historical Permission Notice and Disclaimer - sell variant

## Qt Spatial Audio

Eigen, version 3.4.0 | Mozilla Public License 2.0 and BSD 3-Clause "New" or "Revised" License
Resonance Audio, version e225aedb5ec7 | Apache License 2.0
pfft, version 7641e67977cf937c22849e2ef19fffa70269e562 | BSD 3-Clause "New" or "Revised" License

## Qt Test

Catch2, version 2.13.10 | Boost Software License 1.0
Cycle | MIT License
Linux Performance Events, version 3.7 | GNU General Public License v2.0 only with Linux Syscall Note
Valgrind, version 3.22.0 | BSD 4-clause "Original" or "Old" License

## Qt Virtual Keyboard

OpenWnn | Apache License 2.0
PinyinIME | Apache License 2.0
Traditional Chinese IME (tcime) | Apache License 2.0 and BSD 3-clause "New" or "Revised" License

## Qt Wayland Compositor

Presentation Time Protocol, version 1 | MIT License
Wayland EGLStream Controller Protocol, version 1.1.1 | MIT License
Wayland Fractional Scale Protocol, version 1 | MIT License
Wayland Fullscreen Shell Protocol, version unstable v1 | MIT License
Wayland IVI Extension Protocol, version 1.9.1 | MIT License
Wayland Linux Dmabuf Unstable V1 Protocol, version unstable v1, version 3 | MIT License
Wayland Pointer Gestures Protocol, version unstable v1, version 2 | MIT License
Wayland Primary Selection Protocol, version 1 | MIT License
Wayland Protocol, version 1.19.0 | MIT License
Wayland Scaler Protocol, version 2 | MIT License
Wayland Tablet Protocol, version unstable v2, version 1 | MIT License
Wayland Text Input Protocol v1, version unstable v1 | MIT License
Wayland Text Input Protocol v2, version unstable v2 | HPND License
Wayland Text Input Protocol, version unstable v4, WIP | HPND License
Wayland Viewporter Protocol, version 1 | MIT License
Wayland XDG Foreign Protocol, version 1 | MIT License
Wayland XDG Output Protocol, version unstable v1, version 3 | MIT License
Wayland XDG Shell Protocol, version 1.18 | MIT License
Wayland xdg-activation Protocol, version unstable v1, version 1 | MIT License
Wayland xdg-decoration Protocol, version unstable v1, version 1 | MIT License

## Qt WebEngine

AXE-CORE Accessibility Audit | MPL 2.0
Abseil | Apache 2.0
Alliance for Open Media Video Codec | BSD
Almost Native Graphics Layer Engine | BSD
Android Explicit Synchronization | Apache 2.0
BoringSSL | BSDish
Brotli | MIT
CRC32C | New BSD
Chromium License | BSD
CodeMirror 6 | MIT
Compact Encoding Detection | Apache 2.0
Compact Language Detector v3 | Apache 2.0
Crashpad | Apache 2.0
Dawn | Apache 2.0
Devtools-Frontend | BSD
Emoji Segmenter | Apache 2.0
Expat XML Parser | MIT
Fiat-Crypto: Synthesizing Correct-by-Construction Code for Cryptographic Primitives | MIT
FlatBuffers | Apache 2.0
Google Double Conversion | BSD
Headers for the Windows 10 WebAuthn API (webauthn.dll) | MIT
Highway: C++ library for SIMD | Apache 2.0
Lighthouse | Apache License 2.0
Material color utilities | Apache License 2.0
NVidia Control X Extension Library | MIT
OTS (OpenType Sanitizer) | BSD
One Euro Filter | BSD
PDFium | BSD
PFFFT: a pretty fast FFT. | BSD-like
Perfetto | Apache2
Protocol Buffers | BSD
Recurrent neural network for audio noise reduction | BSD 3-Clause
Snappy: A fast compressor/decompressor | New BSD
The Chromium Project | BSD 3-clause "New" or "Revised" License
The Incremental Distributed Point Functions library | Apache 2.0
V8 fork of fdlibm | Fdlibm license
Volk Meta loader for Vulkan API | MIT
Vulkan Deps | BSD
VulkanMemoryAllocator | MIT
WebKit | BSD and LGPL v2 and LGPL v2.1
WebM container parser and writer. | BSD
WebP image encoder/decoder | BSD
WebRTC | BSD
Wuffs (Wrangling Untrusted File Formats Safely) | Apache 2.0
cpuinfo | BSD
dav1d is an AV1 decoder :) | 2-Clause BSD
dynamic annotations | BSD
ffmpeg | LGPL 2.1
flac | BSD
fontconfig | MIT
google-glog&#x27;s symbolization library | BSD
harfbuzz-ng | MIT
hunspell | MPL 1.1/GPL 2.0/LGPL 2.1
iccjpeg | Custom license
icu | MIT
inspector protocol | BSD
ipcz | BSD
jsoncpp | MIT
libavif - Library for encoding and decoding .avif files | 2-Clause BSD
libevent | BSD
libgav1 | Apache 2.0
libpng | Libpng license
libsrtp | 3-clause BSD
libvpx | BSD
libxml | MIT
libxslt | MIT
libyuv | BSD
mesa_headers | MIT and SGI Free Software B License Version 2.0
minigbm | BSD
modp base64 decoder | BSD
opus | BSD
re2 - an efficient, principled regular expression library | BSD 3-Clause
sqlite | Public domain
woff2 | MIT
xdg-mime | Academic Free License version 2.0 or LGPL v2
xdg-user-dirs | MIT
zlib | Custom license

## Shader Tools

SPIRV-Cross, version sdk-1.3.216.0 | Apache License 2.0 and Khronos License
glslang, version 11.10.0 | BSD 3-Clause "New" or "Revised" License, and Khronos License, and Apache License 2.0, and GNU General Public License v3.0 or later with Bison exception 2.2, and NVIDIA 2002 License

## Additional Information

The following table lists related documents, such as information about Trademarks and other licenses used in parts of Qt.

Android GNU C++ Run-time Licensing | Provides additional information about the licensing of run-time dependencies of Qt for Android
LLVM Attribution | University of Illinois/NCSA Open Source License, BSD licenses
License Changes | Information about changes of licenses in Qt and Third Party Modules
Macros for Building with CMake | BSD 3-clause "New" or "Revised" License
Mesa llvmpipe | MIT License and Boost Software License 1.0
Notes about PDF Licensing | Details of restrictions on the use of PDF-related trademarks
The QtEntryPoint Library | Commercial and BSD 3-clause "New" or "Revised" License.
Trademarks | Information about trademarks owned by The Qt Company.