Qt Documentation

Qt 5.9
Licenses Used in Qt

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 that incorporate code licensed under third-party open-source licenses:

Qt 3D

Open Asset Import Library

BSD 3-clause "New" or "Revised" Licensee

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

Data Compression Library (zlib)	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	BSD 3-clause "New" or "Revised" License
FreeBSD strtoll and strtoull	BSD 3-clause "New" or "Revised" License
MD4	Public Domain
MD5	Public Domain
PCRE2	BSD 3-clause "New" or "Revised" License
PCRE2 - Stack-less Just-In-Time Compiler	BSD 2-clause "Simplified" License
Parts of QTemporaryFile	BSD 3-clause "New" or "Revised" License
QEventDispatcher on macOS	BSD 3-clause "New" or "Revised" License
Secure Hash Algorithm SHA-1	Public Domain
Secure Hash Algorithm SHA-3 - Keccak	Creative Commons Zero v1.0 Universal
Secure Hash Algorithm SHA-3 - brg_endian	BSD 3-clause "New" or "Revised" License
Secure Hash Algorithms SHA-384 and SHA-512	BSD 3-clause "New" or "Revised" License
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
The Public Suffix List	Mozilla Public License 2.0
Unicode Character Database (UCD)	Unicode License Agreement - Data Files and Software (2016)
Unicode Common Locale Data Repository (CLDR)	Unicode License Agreement - Data Files and Software (2016)
forkfd	MIT License

Qt GUI

ANGLE Library	BSD 3-clause "New" or "Revised" License
ANGLE: Array Bounds Clamper for WebKit	BSD 2-clause "Simplified" License
ANGLE: Murmurhash	Public Domain
ANGLE: Systeminfo	BSD 2-clause "Simplified" License
ANGLE: trace_event	BSD 3-clause "New" or "Revised" License
Anti-aliasing rasterizer from FreeType 2	Freetype Project License or GNU General Public License v2.0 only
Cocoa Platform Plugin	BSD 3-clause "New" or "Revised" License
Freetype 2	Freetype Project License or GNU General Public License v2.0 only
Freetype 2 - Bitmap Distribution Format (BDF) support	MIT License
Freetype 2 - Portable Compiled Format (PCF) support	MIT License
Freetype 2 - zlib	zlib License
HarfBuzz	MIT License
HarfBuzz-NG	MIT License
IAccessible2 IDL Specification	BSD 3-clause "New" or "Revised" License
LibJPEG	Independent JPEG Group License
LibPNG	libpng License and libpng License 2
Native Style for Android	Apache License 2.0
OpenGL ES 2 Headers	MIT License
OpenGL Headers	MIT License
Pixman	MIT License
Smooth Scaling Algorithm	BSD 2-clause "Simplified" License and Imlib2 License
Wintab API	Public Domain
XCB	MIT License
xkbcommon	MIT Licenses (with no-advertisement clause)

Qt Image Formats

JasPer	JasPer License
MNG reference library	zlib License
TIFF Software Distribution (libtiff)	libtiff License
WebP (libwebp)	BSD 3-clause "New" or "Revised" License

Qt Location

Boost	Boost Software License 1.0
CSS Color Parser	MIT License
Clip2Tri Polygon Triangulation Library	MIT License
Clipper Polygon Clipping Library	Boost Software License 1.0
Earcut	ISC License
Earcut Polygon Triangulation Library	ISC License
Mapbox GL Native	BSD 2-clause "Simplified" License
Poly2Tri Polygon Triangulation Library	BSD 3-clause "New" or "Revised" License
RapidJSON	MIT License
Vector Tile Library	ISC License
Wagyu Geometry Processing Library	MIT License
cURL Parse Date	MIT License
geojson-cpp	ISC License
geojson-vt-cpp	ISC License
geometry.hpp	ISC License
kdbush.hpp	ISC License
libc++	MIT and UIUC (BSD-like)
polylabel	ISC License
protozero	BSD 2-clause "Simplified" License
shelf-pack-cpp	ISC License
supercluster.hpp	ISC License
unique_resource	Boost Software License 1.0
variant	BSD 3-clause "New" or "Revised" License

Qt Purchasing

Base64 Decoder	Apache License 2.0
In-app billing service	Apache License 2.0
Public Key Verification	Apache License 2.0

Qt QML

JavaScriptCore Macro Assembler

BSD 2-clause "Simplified" License

Qt Quick Controls 2

Shadow values from Angular Material

MIT License

Qt SQL

SQLite

Public Domain

Qt SVG

XSVG	MIT "Old Style" License

Qt Script

JavaScriptCore

GNU Library General Public License v2 or later

Qt Test

Cycle	MIT License
Linux Performance Events	GNU General Public License v2.0 only
Valgrind	BSD 4-clause "Original" or "Old" License

Qt Virtual Keyboard

Lipi Toolkit	MIT License
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

Wayland IVI Extension Protocol	MIT License
Wayland Protocol	HPND License
Wayland Text Input Protocol	HPND License
Wayland XDG Shell Protocol	MIT License

Qt WebEngine

Almost Native Graphics Layer Engine	BSD
Android Explicit Synchronization	Apache 2.0
Blackmagic DeckLink SDK - Mac	BSL (v 1.0)
Brotli	MIT
Chrome Custom Tabs - Example and Usage	Apache 2.0
ChromeVox	Apache 2.0
Chromium License	BSD
Chromium OS system API	BSD
Closure compiler	Apache 2.0
Cocoa extension code from Camino	MPL 1.1/GPL 2.0/LGPL 2.1
Compact Encoding Detection	Apache 2.0
Compact Language Detector v3	Apache 2.0
Crashpad	Apache 2.0
Darwin	Apple Public Source License 2.0
David M. Gay's floating point routines	MIT-like
Error Prone	Apache 2.0
Expat XML Parser	MIT
FlatBuffers	Apache 2.0
Flot Javascript/JQuery library for creating graphs	MIT
GifPlayer Animated GIF Library	Apache License 2.0
Google VR SDK	Apache 2.0
Google fork of Khronos reference front-end for GLSL and ESSL	MIT
Hardware Composer Plus	Apache 2.0
Headless Android Heap Analyzer	Apache 2.0, LGPL 2.1
IAccessible2 COM interfaces for accessibility	BSD
ISimpleDOM COM interfaces for accessibility	MPL 1.1/GPL 2.0/LGPL 2.1
Khronos header files	MIT/X11, SGI Free Software License B
LZMA SDK	Public Domain
LeakCanary	Apache 2.0
LevelDB: A Fast Persistent Key-Value Store	New BSD
NSBezierPath additions from Sean Patrick O'Brien	BSD
NVidia Control X Extension Library	MIT
Netscape Portable Runtime (NSPR)	MPL 1.1/GPL 2.0/LGPL 2.1
Network Security Services (NSS)	MPL 2
OTS (OpenType Sanitizer)	BSD
OpenH264	2-Clause BSD
OpenMAX DL	BSD
PDFium	BSD
PLY (Python Lex-Yacc)	BSD
Paul Hsieh's SuperFastHash	BSD
Protocol Buffers	BSD
Quick Color Management System	MIT
SMHasher	MIT, Public Domain
SPIR-V Tools	MIT
Shaderc	Apache 2.0
Skia	BSD
Snappy: A fast compressor/decompressor	New BSD
Strongtalk	BSD
Sudden Motion Sensor library	University of Illinois/NCSA Open Source License
SwiftShader	Apache 2.0 and compatible licenses
The USB ID Repository	BSD
The library to input, validate, and display addresses.	Apache 2.0
V8 JavaScript Engine	BSD
Vulkan API headers	MIT
WDS	LGPL 2.1
Web Animations JS	Apache 2.0
WebKit	BSD and GPL v2
WebM container parser and writer.	BSD
WebP image encoder/decoder	BSD
WebRTC	BSD
Windows Template Library (WTL)	Microsoft Permissive License
boringssl	BSDish
bspatch	BSD 2-Clause License
d3	BSD 3-Clause
dom-distiller-js	BSD
dynamic annotations	BSD
fdlibm	Freely Distributable
ffmpeg	LGPL 2.1
fips181	BSD 3-Clause
flac	BSD
fontconfig	MIT
gRPC, an RPC library and framework	BSD-style, copyright Google
google-glog's symbolization library	BSD
google-jstemplate	Apache 2.0
harfbuzz-ng	MIT
hunspell	MPL 1.1/GPL 2.0/LGPL 2.1
iccjpeg	Custom license
icu	MIT
inspector protocol	BSD
jsoncpp	MIT
libFuzzer	University of Illinois/NCSA Open Source
libcxx	MIT, University of Illinois/NCSA Open Source License
libcxxabi	MIT, University of Illinois/NCSA Open Source License
libevent	BSD
libjingle	BSD
libjpeg	Custom license
libjpeg-turbo	Custom license
libpng	libpng license
libsecret	LGPL 2.1
libsrtp	3-clause BSD
libudev	LGPL 2.1
libusbx	LGPL 2.1
libva	MIT
libvpx	BSD
libxml	MIT
libxslt	MIT
libyuv	BSD
linux-syscall-support	BSD
mach_override	MIT and 2-clause BSD
mesa	MIT and LGPL v2
minigbm	BSD
modp base64 decoder	BSD
mt19937ar	BSD
open-vcdiff	Apache 2.0, MIT, GPL v2 and custom licenses
opus	BSD
re2 - an efficient, principled regular expression library	BSD 3-Clause
sfntly	Apache 2.0
simplejson	MIT
sqlite	Public domain
tcmalloc	BSD
tlslite	Public domain and BSD
url_parse	BSD and MPL 1.1/GPL 2.0/LGPL 2.1
usrsctp	New BSD
v4l-utils	LGPL 2.1
valgrind	BSD
wayland	MIT
wayland-protocols	MIT
woff2	Apache 2.0
x86inc	ISC from text in file header. Same text is copied to LICENSE file.
xdg-mime	Academic Free License version 2.0 or LGPL v2
xdg-user-dirs	MIT
xdg-utils	MIT
yasm	2-clause or 3-clause BSD licensed, with the exception of bitvect, which is triple-licensed under the Artistic license, GPL, and LGPL
zlib	Custom license

Qt XML Patterns

XML Schema

W3C Software Notice and Document License (2015-05-13)

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
Contributions to the Cocoa Platform Plugin Files	License information for contributions by Apple, Inc. to specific parts of the Qt for macOS Cocoa port.
Flite Library
Macros for Building with CMake	BSD 3-clause "New" or "Revised" License
Mesa llvmpipe	MIT License
Notes about PDF Licensing	Details of restrictions on the use of PDF-related trademarks.
Open Source Licensing of Qt	Information about open source licensing of Qt.
The qtmain Library	Commercial and BSD 3-clause "New" or "Revised" License.
Trademarks	Information about trademarks owned by The Qt Company and other organizations.

© 2019 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners. The documentation provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation. Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners.