The NetHack 4 engine and interface are licensed under the NetHack General Public License (NGPL). This license gives you the right to redistribute and modify it, so long as you obey certain terms and conditions. The full text of the NGPL is given later in this document.
NetHack 4 also uses certain libraries: libuncursed, zlib, libjansson, and (if you install the GUI support) SDL2 and libpng. (libpng is also used by the tileset compiler.) libuncursed is multi-licensed, offering the NGPL as one possible license, and is used here under the NGPL. The other libraries have other licenses, given later in this document.
Installing GUI support allows you to play in a "fake terminal", rather than just on the console. If you install a tileset, it will also allow you to play with a map represented by "tiles" images rather than text. One of these tilesets, "Slash'EM", is licensed under the NGPL. The others have licenses of their own, given later in this document.
The documentation is also under this license (except where it quotes existing licenses verbatim), and © Alex Smith 2013, 2014, 2015.
For a more detailed version of this document, including the individual copyright status of every source file, see the "copyright-details.txt" file after installation (in the "nethack4\doc" subdirectory of your Program Files directory). You can find this file as "license.rtf" in the same subdirectory after installation.
There is no warranty for NetHack 4 or any of its component parts.
The NetHack 4 engine and interface are © Stichting Mathematisch Centrum, Amsterdam, 1985; © Alex Smith 2010-2015; © Daniel Thaler 2011-2012; and many other contributors. The full list of contributors is available in the "history" document, viewable in-game.
The tiles compiler is also under this license, and © Alex Smith 2014; © Andrew Apted <ajapted@users.sourceforge.net> 2002; © Slash'EM Development Team 2003; © Stichting Mathematisch Centrum, Amsterdam, 1985; © Robert Patrick Rankin 1991.
The Slash'EM tileset and the font used by the fake tiles port are also under this license. The full list of artists is unknown, but believed to include: Warwick Allison; Mitsuhiro Ikatura; Haruko Numata; Edger; ZMYDaino; Wan'ichi; Tatsuya; Kelly Youngblood; Paul Pliska; John Harris; Andrew Walker; and Alex Smith. Known copyright dates range from 2000 to 2014. For more information, see the "copyright.txt" file after installation.
NETHACK GENERAL PUBLIC LICENSE
(Copyright 1989 M. Stephenson)
(Based on the BISON general public license,
copyright 1988 Richard M. Stallman)
Everyone is permitted to copy and distribute verbatim copies of this
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Permission is hereby granted, free of charge, to any person obtaining a copy
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This copy of the libpng notices is provided for your convenience. In case of
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COPYRIGHT NOTICE, DISCLAIMER, and LICENSE:
If you modify libpng you may insert additional notices immediately following
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This code is released under the libpng license.
libpng versions 1.2.6, August 15, 2004, through 1.5.10, March 29, 2012, are
Copyright (c) 2004, 2006-2011 Glenn Randers-Pehrson, and are
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libpng versions 0.97, January 1998, through 1.0.6, March 20, 2000, are
Copyright (c) 1998, 1999 Glenn Randers-Pehrson, and are
distributed according to the same disclaimer and license as libpng-0.96,
with the following individuals added to the list of Contributing Authors:
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Glenn Randers-Pehrson
Willem van Schaik
libpng versions 0.89, June 1996, through 0.96, May 1997, are
Copyright (c) 1996, 1997 Andreas Dilger
Distributed according to the same disclaimer and license as libpng-0.88,
with the following individuals added to the list of Contributing Authors:
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libpng versions 0.5, May 1995, through 0.88, January 1996, are
Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.
For the purposes of this copyright and license, "Contributing Authors"
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Andreas Dilger
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The PNG Reference Library is supplied "AS IS". The Contributing Authors
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Permission is hereby granted to use, copy, modify, and distribute this
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1. The origin of this source code must not be misrepresented.
2. Altered versions must be plainly marked as such and must not
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3. This Copyright notice may not be removed or altered from any
source or altered source distribution.
The Contributing Authors and Group 42, Inc. specifically permit, without
fee, and encourage the use of this source code as a component to
supporting the PNG file format in commercial products. If you use this
source code in a product, acknowledgment is not required but would be
appreciated.The DawnLike tileset is © Andrew Rios 2014 (art), © Alex Smith 2014 (tile selection and organization). The tiles are licensed under a mix of Creative Commons licenses: Creative Commons Attribution 3.0 Unported (tiles originally from an older version, DawnHack), and Creative Commons Attribution-Share Alike 3.0 Unported (tiles from DawnLike). Here's what the artist had to say about the copyright status:
Dawnlike is registered under a CC-BY-SA 3.0 license, meaning that you
are free to redistribute or edit any part of this tileset as long as
you do not take the credit for it. I cannot stop you from using this
tileset commercially, so feel free to sell any games using Dawnlike.
If you use this tileset you must accredit DawnBringer. That mad
color-bending genius came up with the palette this entire pack lives
on. Without his palette, I would probably never would have even
finished DawnHack. As for crediting me, I have a unique
request. Inside "Reptiles.png" you will find a Platino sprite. If you
use Dawnlike, you MUST use this sprite and hide him very well!You can view the Creative Commons licenses in question at http://creativecommons.org/licenses/by/3.0/ (Attribution) and http://creativecommons.org/licenses/by-sa/3.0/ (Attribution-Share Alike), or by sending a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California 94105, USA.
The version of the RLTiles tileset in NetHack 4 was produced by Raz in 2014 and 2015, with some coding by Alex Smith. It was derived from the original version of RLTiles, which had the following license information:
You can use these tilesets in your program freely. Please include the
following text in your distribution package, either as a separate
file or incorpolated into your license notice document. The fourth
line is optional: Delete it if you have not modified the tiles. If
you have modified some of the tiles, replace "YOURNAME" by your name.
Part of (or All) the graphic tiles used in this program is the public
domain roguelike tileset "RLTiles".
Some of the tiles have been modified by Raz.
You can find the original tileset at:
http://rltiles.sf.netThe list of contributors to the original RLTiles was:
Denzi
=========
dwarf lord, watchman, watch captain, page, raven,
*About half of the Dungeon Crawl tiles*
*Allmost all the player tiles*
Alex Korol
=========
dc/abomination*.bmp, 64x64 stairs tile, 64x64 swamp dragon
Edger
=========
Cerberus
Wan-ichi
=========
werejackal, werewolf, leocrotta, wumpus,
titanothere, baluchitherium, wererat
So-Miya
=========
chickatrice, pyrolisk, vampire, vampire mage
storm giant, silver dragon scale mail, shimmering dragon scale mail
silver dragon scales, shimmering dragon scales, baby shimmering dragon
shimmering dragon, baby silver dragon, silver dragon
master mind flayer, leather cloak, magcal explosions
Haruko Numata
=========
rope golem, leather golem, flesh golem, clay golem
stone golem, horned devil,
Lord Carnarvon, Pelias, Shaman Karnov, Hippocrates,
King Arthur, Arch Priest, Master of Thieves, Norn, Wizard of Balance,
low boots, iron shoes, high boots, combat boots, jungle boots,
hiking boots, mud boots
Tatsuya
=========
knight(3D), samurai(3D), barbarian(3D)
hill giant(3D), dragons(3D)
from AllegroHack (Kelly Youngblood, Paul Pliska, John Harris)
=========
gas spore, flaming sphere, shocking sphere
Dainokata
=========
warg, manes, shrieker,
water moccasin, elf zombie,human zombie,
straw golem, iron golem, wererat, shopkeeper,
guard, iguana, caveman, healer, rogue,
tourist, dart, aklys, elven bow,
orcish bow, elven cloak,
orcish cloak, opera cloak, sack,
lock pick, lamp, blindfold, towel,
leash, stethoscope, tinning kit, figurine,
cram ration, food ration, statue, alter, sink
Zmy
=========
dog, large dog, bugbear, rothe, ape, owlbear,
skeleton, Woodland-elf, Green-elf, Grey-elf,
Croesus, marilith, vrock, hezrou, nalfeshnee, Orcus,
Demogorgon, cavewoman, Elwing, dwarvish mattock,
pickaxe, Kop Lieutenant, Kop Sergeant, elf-lord
Oracle, Archon, Snake, pyton, cobra, Earendil