Interestingly, Quake 3 did use a double sided stack allocator as the article describes. The engine made one big allocation at startup called the "hunk." The "low hunk" allocated long-lived data and the "high hunk" temporary data. Search for "hunk" in this source file to see the implementation [1].
[1] https://github.com/id-Software/Quake-III-Arena/blob/master/c...
In The Double Headed Stack Allocatorid-Software
Quake-III-Arena
C2012–2026
id-Software / Quake-III-Arena
Quake-III-Arena
Quake III Arena GPL Source Release
35Distinct people
37Mentions
2Explicit recommenders
8.3KGitHub stars
What to know before exploring
What it is
Quake III Arena GPL Source Release
GitHub
Where it is used
No documented product use was verified in the last source check.
What people are saying
Interesting paper. The following code is probably my favorite, "What will this program output?" example. This is taken from the Quake III Arena code in "q_math.c" [1]. Note…
Arjuna used a recommendation phrase. 2 indexed comments match. This is a phrase match, not a verdict.
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This week on Hacker News
Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 5:04:57 PM UTC.
No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.
Mentions over time
HN mentions by year37 dated mentions
Observed mentions: 2012-02-01 14:09:40 UTC to 2026-10-15 17:37:20 UTC.
* An incomplete calendar period is marked with an outlined bar. Its count is not directly comparable with a full period.
Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.
View mention counts and date ranges
| Period | Start (UTC) | End (exclusive, UTC) | Mentions | Submissions | Comments |
|---|---|---|---|---|---|
| 2012 | 2012-01-01 00:00:00 UTC | 2013-01-01 00:00:00 UTC | 3 | 1 | 2 |
| 2013 | 2013-01-01 00:00:00 UTC | 2014-01-01 00:00:00 UTC | 4 | 0 | 4 |
| 2014 | 2014-01-01 00:00:00 UTC | 2015-01-01 00:00:00 UTC | 2 | 1 | 1 |
| 2015 | 2015-01-01 00:00:00 UTC | 2016-01-01 00:00:00 UTC | 1 | 0 | 1 |
| 2016 | 2016-01-01 00:00:00 UTC | 2017-01-01 00:00:00 UTC | 1 | 0 | 1 |
| 2017 | 2017-01-01 00:00:00 UTC | 2018-01-01 00:00:00 UTC | 2 | 0 | 2 |
| 2018 | 2018-01-01 00:00:00 UTC | 2019-01-01 00:00:00 UTC | 8 | 1 | 7 |
| 2019 | 2019-01-01 00:00:00 UTC | 2020-01-01 00:00:00 UTC | 1 | 0 | 1 |
| 2020 | 2020-01-01 00:00:00 UTC | 2021-01-01 00:00:00 UTC | 2 | 0 | 2 |
| 2021 | 2021-01-01 00:00:00 UTC | 2022-01-01 00:00:00 UTC | 5 | 0 | 5 |
| 2022 | 2022-01-01 00:00:00 UTC | 2023-01-01 00:00:00 UTC | 2 | 0 | 2 |
| 2023 | 2023-01-01 00:00:00 UTC | 2024-01-01 00:00:00 UTC | 1 | 0 | 1 |
| 2024 | 2024-01-01 00:00:00 UTC | 2025-01-01 00:00:00 UTC | 3 | 0 | 3 |
| 2025 | 2025-01-01 00:00:00 UTC | 2026-01-01 00:00:00 UTC | 1 | 0 | 1 |
| 2026 (partial) | 2026-01-01 00:00:00 UTC | 2027-01-01 00:00:00 UTC | 1 | 0 | 1 |
From the project README
An excerpt from the repository, fetched Nov 13, 2026.
Read the project’s introduction
Quake III Arena GPL source release
==================================
This file contains the following sections:
LICENSE
GENERAL NOTES
COMPILING ON WIN32
COMPILING ON GNU/LINUX
COMPILING ON MAC
LICENSE
=======
See COPYING.txt for the GNU GENERAL PUBLIC LICENSE
Some source code in this release is not covered by the GPL:
IO on .zip files using portions of zlib
-----------------------------------------------------------------------------
lines file(s)
4299 code/qcommon/unzip.c
4546 libs/pak/unzip.cpp
Copyright (C) 1998 Gilles Vollant
zlib is Copyright (C) 1995-1998 Jean-loup Gailly and Mark Adler
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
MD4 Message-Digest Algorithm
-----------------------------------------------------------------------------
lines file(s)
299 code/qcommon/md4.c
277 common/md4.c
Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All rights reserved.
License to copy and use this software is granted provided that it is identified
as the <93>RSA Data Security, Inc. MD4 Message-Digest Algorithm<94> in all mater
ial mentioning or referencing this software or this function.
License is also granted to make and use derivative works provided that such work
s are identified as <93>derived from the RSA Data Security, Inc. MD4 Message-Dig
est Algorithm<94> in all material mentioning or referencing the derived work.
RSA Data Security, Inc. makes no representations concerning either the merchanta
bility of this software or the suitability of this software for any particular p
urpose. It is provided <93>as is<94> without express or implied warranty of any
kind.
checksums are used to validate pak files
standard C library replacement routines
-----------------------------------------------------------------------------
lines file(s)
1324 code/game/bg_lib.c
Copyright (c) 1992, 1993
The Regents of the University of California. All rights reserved.
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
1. Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
3. All advertising materials mentioning features or use of this software
must display the following acknowledgement:
This product includes software developed by the University of
California, Berkeley and its contributors.
4. Neither the name of the University nor the names of its contributors
may be used to endorse or promote products derived from this software
without specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
SUCH DAMAGE.
ADPCM coder/decoder
-----------------------------------------------------------------------------
lines file(s)
330 code/client/snd_adpcm.c
Copyright 1992 by Stichting Mathematisch Centrum, Amsterdam, The
Netherlands.
All Rights Reserved
Permission to use, copy, modify, and distribute this software and its
documentation for any purpose and without fee is hereby granted,
provided that the above copyright notice appear in all copies and that
both that copyright notice and this permission notice appear in
supporting documentation, and that the names of Stichting Mathematisch
Centrum or CWI not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior permission.
STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO
THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS, IN NO EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE
FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
JPEG library
-----------------------------------------------------------------------------
code/jpeg-6
libs/jpeg6
Copyright (C) 1991-1995, Thomas G. Lane
Permission is hereby granted to use, copy, modify, and distribute this
software (or portions thereof) for any purpose, without fee, subject to these
conditions:
(1) If any part of the source code for this software is distributed, then this
README file mu
Read the full README on GitHubWhat Hacker News says
37 sourcesQuake III Arena was released in 1999. It was open-sourced in 2005.
https://github.com/id-Software/Quake-III-Arena
https://en.wikipedia.org/wiki/Id_Tech_3
(from the source release you can see benreesman remembered right: it was lcc)
In Jank is C++To save everyone a lot of time and OP some money, here is https://github.com/id-Software/Quake-III-Arena diagrammed:
https://gitdiagram.com/id-Software/Quake-III-Arena
https://imgur.com/a/gwoabtk
Clicking on any box takes you directly to either a file or a folder in the repo. AFAICT, the boxes, wires, groups, labels are all inferred by the AI.
In Show HN: Instantly visualize any codebase as an interactive diagramdoes anyone have links to a canonical implementation of modern-style first person controls? I’ve been looking into this recently (both the WASD+mouselook PC version and the corresponding dual-stick console/touch version) and the closest I’ve found so far is ID’s cl_input.c [0] (used in quake, half life, etc.)
[0] https://github.com/id-Software/Quake-III-Arena/blob/master/c...
In How WASD became the standard PC control scheme (2016)You can't copyright a mathematical operation. Only a particular implementation of it, and even then it may not be copyrightable if its a straightforward and obvious implementation.
That said the implementation doesn't appear to be totally trivial and copilot apparently even copies the comments which are almost certainly copyrightable in themselves.
https://x.com/StefanKarpinski/status/1410971061181681674
https://github.com/id-Software/Quake-III-Arena/blob/dbe4ddb1...
However a twitter post on its own isn't evidence a court will accept. You would need the original poster to testify that what is seen in the post is actually what he got from copilot and not just a meme or joke that he made.
Also the plaintiffs in this case don't include id-Software and there is some evidence that id-Software actually stole the fast inverse sqrt code from 3df
Read the rest
x so they might not want to bring a claim here anyways.
It exists in the Q3A code:
https://github.com/id-Software/Quake-III-arena/blob/master/c...
In What every programmer should know about memory (2007) [pdf]Also related: Quake III fast inverse square root[1].
[1]: https://github.com/id-Software/Quake-III-Arena/blob/master/c...
In Fast midpoint between two integers without overflowAfter learning C, one of the first projects I came into contact with, was the ID Tech 3 game engine [1]
On the one hand, it taught me how professional C programmers structure their code (extra functions to remove platform differences, specific code which is being shared between server and client to allow smooth predictions) and how incredible fast computers can be (thousands of operations within milliseconds), but it also showed me, how the same code can result in different executions due to compiler differences (tests pass, production crashes) and how important good debugging tools are (e.g. backtraces).
To this day I am very grateful for the experience and that ID decided to release the code as open source.
[1] https://github.com/id-Software/Quake-III-Arena
In Everything I wish I knew when learning Chttps://github.com/id-Software/Quake-III-Arena/blob/dbe4ddb1...
561 i = 0x5f3759df - ( i >> 1 ); // what the fuck?
In Fast Inverse Square RootIt’s interesting how fairly complex bit twiddling hacks are well-known for integers, but even very simple but useful bit twiddles for floats (like this one) are obscure enough to warrant their own article.
Of course, the most famous bit manipulation of floats is the fast inverse square root trick [0]. The bits of a float as an integer literal are proportional to its log2 value (plus a constant), which is handy for computing a reciprocal square root in logspace, which when converted back to a float gets exponentiated, yielding the answer (after a couple more refinement steps). If you actually take the time to manually hammer out the bitwise manipulations, the fast inverse square root is quite simple, but it is nonetheless regarded as black magic, likely due to the totally non-explanatory comments in the Quake source code.
Funnily enough, d
Read the rest
irectly following the fast inverse square root in the Quake source code is a function to compute absolute values by zeroing the float sign bit [1], just as described in the article.
[0] https://en.wikipedia.org/wiki/Fast_inverse_square_root#Alias...
[1] https://github.com/id-Software/Quake-III-Arena/blob/dbe4ddb1...
Look at all the instances of "next" in this file: https://github.com/id-Software/Quake-III-Arena/blob/dbe4ddb1...
In I had to give a wrong answer to get the job (2017)The RMS function in Quake Source code exists in the copilot training set (see https://news.ycombinator.com/item?id=27710287) is covered under GPL which is source available (see https://github.com/id-Software/Quake-III-Arena/blob/master/c...)
In I do not agree with Github's use of copyrighted code as training for CopilotFrom the GPLv2 licensed code:
https://github.com/id-Software/Quake-III-Arena/blob/master/c...
copilot repeats it word for word almost, including comments, and adds an MIT like license up the top
In Copilot regurgitating Quake code, including sweary commentsQuake III is always fun reading: https://github.com/id-Software/Quake-III-Arena
In Ask HN: Good C++ code bases to read?Not at all, Quake 3's source code is GPL[1]. You can totally sell a game made with Quake 3's source, you just have to redistribute the source as mandated by the GPL. v{6}'s license is more restrictive.
The assets are a different problem. You can use the code without the assets and vice-versa.
[1] https://github.com/id-Software/Quake-III-Arena/blob/master/C...
In VVVVVV’s source code is now public, 10 year anniversary jam happening nowShowing the 15 most recent of 37 sources. Enable JavaScript to search and browse every indexed mention.