DOSBox Staging License
----------------------

The DOSBox Staging project is a fork of the DOSBox project, and as
such, all works derived from the DOSBox project carry the same
license terms as granted by the DOSBox authors, which is the "GNU
General Public License version 2 or later" (GPL-2.0-or-later).

Original works authored by the DOSBox Staging team are also
licensed under the GPL-2.0-or-later terms to maximize portability
of code with both upstream and other DOSBox forks.

Most third party libraries used by Staging are licensed under the
GPL-2.0-or-later terms, however there are some exceptions:

- MAME's Philips SAA1099 and Texas Instruments SN76489 emulators,
  under the src/hardware/audio/mame and src/hardware/audio/private/mame
  directories, are both licensed under the BSD 3-Clause terms.

- MAME's 3dfx Voodoo Graphics emulator by Aaron Giles, in file
  src/hardware/video/voodoo.cpp, which is licensed under the
  BSD-3-Clause AND GPL-2.0-or-later terms.

- MandrakeSoft's National Semiconductor NE2000 emulator, in file
  src/hardware/network/ne2000.cpp, which is licensed under the
  LGPL-2.1-or-later terms.

- DOS code pages to Unicode mapping definition files in the
  resources/mapping-unicode.org directory are licensed under the
  Unicode, Inc. License Agreement for Data Files and Software license.

- Libraries in src/libs directory, are licensed as follows:
   - base64: MIT
   - clap headers: MIT
   - decoders/dr_flac.h, dr_mp3.h, dr_wav.h: Public Domain or MIT
   - decoders/stb.h, stb_vorbis.h: Public Domain
   - enet: MIT
   - ESFMu: LGPL-2
   - glad: (WTFPL OR CC0-1.0) AND Apache-2.0
   - http: MIT
   - json: MIT
   - libslirp headers: BSD 3-Clause
   - loguru: Public Domain
   - ManyMouse: Zlib
   - mverb: GPL-3
   - Nuked OPL3: LGPL-2
   - PDcurses: Public Domain
   - PL_MPEG: MIT
   - residfp: GPL-2
   - riffcpp: Zlib
   - simde: MIT
   - simpleini: MIT
   - stb_truetype: MIT or Public Domain
   - tal-chorus: GPL-2
   - whereami: MIT or WTFPL
   - YM7128B_emu: BSD 2-Clause

The above licenses meet GNU's qualifications for being free
software (https://www.gnu.org/licenses/license-list.en.html) and
are compatible with the GNU GPL.


Bundled Binaries Licenses
-------------------------

The following 3rd party binaries are shipped with DOSBox Staging:

- DOS command binaries in resources/drives/y/dos, are licensed as follows:
   - debug.com: licenses/DEBUG.COM.txt, source code: https://github.com/Baron-von-Riedesel/DOS-debug
   - deltree.com: GPL-2.0, source code: https://gitlab.com/FreeDOS/base/deltree
   - xcopy.exe: GPL-2.0, source code: https://github.com/joncampbell123/dosbox-x/tree/master/src/builtin/xcopy

- FreeDOS CPI files in resources/freedos-cpi are GPL-2.0 licensed;
  these are hand-drawn bitmap fonts, so they don't have a source code; original repositories:
   - https://gitlab.com/FreeDOS/base/cpidos (the main code page pack)
   - https://github.com/FDOS/cpi (ISO/KOI/MAC/WIN code page packs)
  The code page files were originally in the CPX format, they were decompressed into the CPI format.

- FreeDOS keyboard layout files in resources/freedos-keyboard are GPL-2.0 licensed;
  source code: https://gitlab.com/FreeDOS/base/keyb_lay

The DOSBox Staging repository contains full snapshots of the original
repositories in the extras/dos-programs directory.


Individual Source File Licenses 
-------------------------------

The license of each individual DOSBox Staging source file can be
found in the first few lines after "SPDX-License-Identifier". The
full text for each license can be found in the licenses/
directory.

Some libraries have their own COPYING or LICENSE file in their
respective subdirectories, however, when not available, the license
is described in the source files themselves.

See also https://spdx.org/licenses/ for the full license texts,
and https://spdx.org/ids for the standardized header format.


License Compatibility
---------------------

As depicted in GNU's license compatibility flow chart [1],
answered in their frequently asked questions [2], and described
in each licenses' text, we understand that the following license
changes are permitted:

 - LGPL-2.1-or-later -> GPL-2.0-or-later -> GPL-3.0-or-later

 - LGPL-3.0-or-later -> GPL-3.0-or-later

Taken as a whole, the compiled binaries of DOSBox Staging project
are covered by the terms of GPL-2.0-or-later license.

[1] "A Quick Guide to GPLv3", GNU license FAQ website, GNU
    Organizion, accessed 1 July 2022,
    https://www.gnu.org/licenses/quick-guide-gplv3.en.html.

[2] "Frequently Asked Questions about the GNU Licenses", GNU
    license FAQ website, GNU Organizion, accessed 1 July 2022,
    https://www.gnu.org/licenses/gpl-faq.html#AllCompatibility.