Qt API | Qtopia API | Qtopia Documentation |

# 3rd Party Licenses used in Qt

Run `configure -help` to see any options that may be available for controlling the use of these libraries.

- Freetype 2 (freetype)
- The Independent JPEG Group's JPEG software (libjpeg)
- Multiple-image Network Graphics (MNG) Reference Library (libmng)
- PNG reference library (libpng)
- Data compression library (zlib)

## Freetype 2 (freetype)

The FreeType project provides font rendering for Qt. FreeType is distributed under either the FreeType Project License or the GNU Public License. The primary copyright holders are David Turner (david.turner@freetype.org), Robery Wilhelm and Werner Lemberg. More information can be found at http://www.freetype.org and `3rdparty/freetype/docs/freetype2.html`.

Qt optionally links against FreeType.

See `3rdparty/freetype/docs/FTL.txt` and `3rdparty/freetype/docs/GPL.txt` for license details.

See also the files in `3rdparty/opentype` which are used by Freetype.

## The Independent JPEG Group's JPEG software (libjpeg)

This package contains C software to implement JPEG image compression and decompression. JPEG (pronounced "jay-peg") is a standardized compression method for full-color and gray-scale images. JPEG is intended for compressing "real-world" scenes; line drawings, cartoons and other non-realistic images are not its strong suit. JPEG is lossy, meaning that the output image is not exactly identical to the input image. -- quoted from `3rdparty/libjpeg/README`.

Qt optionally links against libjpeg to order to provide JPEG viewing and writing.

libjpeg is the work of Tom Lane, Philip Gladstone, Jim Boucher, Lee Crocker, Julian Minguillon, Luis Ortiz, George Phillips, Davide Rossi, Guido Vollbeding, Ge' Weijers, and other members of the Independent JPEG Group.

See `3rdparty/libjpeg/README` for license details.

## Multiple-image Network Graphics (MNG) Reference Library (libmng)

The libmng library supports decoding, displaying, encoding, and various other manipulations of the Multiple-image Network Graphics (MNG) format image files. It uses the zlib compression library, and optionally the JPEG library by the Independant JPEG Group (IJG) and/or lcms (little cms), a color-management library by Marti Maria Saguer. -- quoted from `3rdparty/libmng/doc/libmng.txt`.

Qt optionally links against libmng to order to provide JPEG viewing and writing.

The primary copyright holder for libmng is Gerard Juyn (gerard@libmng.com), and it is distributed under a very free license.

See `3rdparty/libmng/LICENSE` for license details.

## PNG reference library (libpng)

Libpng was written as a companion to the PNG specification, as a way of reducing the amount of time and effort it takes to support the PNG file format in application programs. -- quoted from `3rdparty/libpng/libpng.txt`.

Qt optionally links against libpng to order to provide JPEG viewing and writing.

The primary copyright holder for libpng is Glenn Randers-Pehrson, and it is distributed under a very free license.

See `3rdparty/libpng/LICENSE` for license details.

## Data compression library (zlib)

zlib is a general purpose data compression library. All the code is thread safe. The data format used by the zlib library is described by RFCs (Request for Comments) 1950 to 1952 -- quoted from `3rdparty/zlib/README`.

Qt optionally links against libz to support libmng.

The primary copyright holders for zlib are Jean-loup Gailly and Mark Adler, and it is distributed under a very free license.

See `3rdparty/zlib/README` for license details.