Justine Tunney
justine.lol · Personal blog · on HN since 2020
Justine Tunney writes on portable executables, Cosmopolitan Libc, pledge on Linux, and fast LLM inference on CPUs.
What HN saysHN commenters call her a brilliant hacker and recommend her site, linking her APE and pledge posts and a Threadripper build.
251HN people shared it
210linked it in comments
80stories submitted
13Kstory points
3 months agolast shared
2020people per year2026
Most-shared posts
- 1Actually Portable Executable80 people · 678 points · first shared 2020 · 162 comments on HN
- 2Cosmopolitan Libc: build-once run-anywhere C library21 people · 603 points · first shared 2020 · 166 comments on HN
- 3Show HN: Porting OpenBSD Pledge() to Linux18 people · 577 points · first shared 2022 · 128 comments on HN
- 4Cosmopolitan Libc: your build-once run-anywhere C library18 people · 98 points · first shared 2020 · 11 comments on HN
- 5Homepage15 people · first shared 2021
- 6Blinkenlights: PC Binary Emulating Visualizer14 people · 144 points · first shared 2021 · 26 comments on HN
- 7Cosmopolitan Third Edition14 people · 35 points · first shared 2023 · 12 comments on HN
- 8LLaMA now goes faster on CPUs12 people · 1.4K points · first shared 2024 · 451 comments on HN
- 9Lambda Calculus in 400 Bytes12 people · 885 points · first shared 2022 · 63 comments on HN
- 10Show HN: Lisp with GC in 436 Bytes12 people · 737 points · first shared 2021 · 131 comments on HN
- 11Show HN: SectorLISP now fits in one sector9 people · 323 points · first shared 2021 · 75 comments on HN
- 12Show HN: Redbean – Single-file distributable web server8 people · 2.0K points · first shared 2020 · 249 comments on HN
- 13Redbean 2.0 turned into more than a hobby project6 people · 1.0K points · first shared 2022 · 224 comments on HN
- 14Can I use a system call?6 people · 581 points · first shared 2022 · 158 comments on HN
- 15Supporting four operating systems in a 400 byte ELF executable6 people · 327 points · first shared 2022 · 42 comments on HN
What HN people wrote when they linked it
kristianp · 2023-04-01
Looks like the mmap functionality was done by the same person as https://justine.lol what a great hacker!
Edit:
Dup of https://news.ycombinator.com/item?id=35393284
nine_k · 2025-01-13
Let me also add the brilliant https://justine.lol
dan_sbl · 2026-05-31
Love how the 512 GB of RAM documented in one of his setups as costing $2,776 now sells for $18,299. https://justine.lol/rseq/threadripper.html
isityettime · 2026-05-30
One of HN's favorite hackers has done that: https://justine.lol/pledge/
There was a discussion here about it a few years ago: https://news.ycombinator.com/item?id=32096801
gegtik · 2026-01-18
Naturally this makes me think of the brilliant Justine Tunney's https://justine.lol/ape.html / https://github.com/jart/cosmopolitan / https://redbean.dev/
jart · 2026-01-05
What are you going off? CPI? For thousands of years gold has been the benchmark of currencies. For example you can read the Code of Hammurabi from Ancient Babylon where they used gold and silver as their currency, and then convert the figures mentioned in their laws. You'd be surprised by how invariant everything seems. https://justine.lol/inflation/ CPI isn't a trustworthy indicator. The government can't tell the truth about inflation because retirees all own TIPS so the government would have to pay them obscene amounts of money if the official numbers went up, which it can't afford, because the whole reason the government is debasing the currency in the first place is to pay for all the other benefits it gives to retirees.
bjconlan · 2025-03-22
This is where I need to shout out to everyone's favorite developer Justine for keeping Linux cool:
https://justine.lol/pledge/
Which also points to landlock-make[0] or vice-versa (the original project that made me aware of the kernel functionality (although didn't realize it also isolated network which is great).
[0]https://justine.lol/make/
smurpy · 2024-12-31
Fascinating exercise and nice work!
Adjacent (resilient, low-level, big-vision, auditable) projects include:
http://collapseos.org/ Forth OS, bootstrapable from paper, for z80
https://urbit.org/ standalone, distributed, auditable, provable, minimalist
https://justine.lol/ APE (actually portable executable); cosmopolitan libc
chubot · 2024-09-24
I'm pretty sure it is, I remember reading something about this
Yeah I found it here
https://news.ycombinator.com/item?id=41030960
2019 bug - https://austingroupbugs.net/view.php?id=1250
https://justine.lol/cosmo3/
> This is an idea whose time has come; POSIX even changed their rules about binary in shell scripts specifically to let us do it.
FWIW I agree with this OpenBSD change, which says more pointedly
All the shells are written in C, and majority of them use C strings for everything, which means they cannot embed a NUL, so this is not surprising. It is quite unbelievable there are people trying to rewrite history on a lark, and expecting the world to follow alone.
i.e. it's not worth it to change a bunch of old code in order to allow making code more esoteric.
We want systems code to be more predictable, reliable, and less esoteric ... not more esoteric
syvon · 2024-09-18
Hi!
One of the original author of Ribbit here, glad to see it is still getting attention. Léonard and Marc took the project much further than I imagined.
As a fun fact, the project started as a riff of Justine Tunney's famous https://justine.lol/sectorlisp/.
For the interested, my new favorite project from Marc's team is https://github.com/udem-dlteam/pnut
tazu · 2024-08-19
I've personally been very motivated to learn C (coming from Go) by witnessing @jart's[1] progress on Cosmopolitan[2] and Readbean[3]. Writing C is almost like an exercise in sovereignty: ultimate freedom (and danger).
[1]: https://justine.lol/
[2]: https://github.com/jart/cosmopolitan
[3]: https://news.ycombinator.com/item?id=26271117
AstroJetson · 2024-07-10
Check out Justine Tunney and her emulator. https://justine.lol/blinkenlights/
The docs are an amazing tour of how the cpu works.
yjftsjthsd-h · 2024-06-24
And this kind of beautiful insanity is why you're one of my favorite developers of this era.
Also,
> I'm already putting the ARM code inside all my binaries.
Wait, I thought CPU architecture was the one limitation that did affect APE - you mean on unix-likes APE binaries are already compatible across amd64 and aarch64?
Edit: rereading https://justine.lol/cosmo3/ it does say that, doesn't it - and ARM64 listing "Windows (non-native)" just means that one platform uses (for the next few hours-days, at least...) emulation. That's amazing:)
d416 · 2024-04-02
love this site. Check out Justine Tunney’s blog posts for pre-processing content filtering with AI using bash commands:
http://justine.lol/oneliners/
http://justine.lol/matmul/
adolph · 2024-02-02
For folks interested in this topic who have not seen Cosmopolitan and RedBean, αcτµαlly pδrταblε εxεcµταblε (2020) is a great read too: https://justine.lol/ape.html
https://redbean.dev/
lioeters · 2024-01-23
Indeed, Cosmopolitan C is amazing.
> Cosmopolitan Libc makes C a build-anywhere run-anywhere language, like Java, except it doesn't need an interpreter or virtual machine. Instead, it reconfigures stock GCC and Clang to output a POSIX-approved polyglot format that runs natively on Linux + Mac + Windows + FreeBSD + OpenBSD + NetBSD + BIOS on AMD64 and ARM64 with the best possible performance.
https://justine.lol/cosmopolitan/
bambax · 2024-01-03
> targeting a lot of platforms
Wouldn't a project such as this one be a perfect candidate for Cosmopolitan?
> Cosmopolitan Libc makes C a build-anywhere run-anywhere language, like Java, except it doesn't need an interpreter or virtual machine. Instead, it reconfigures stock GCC and Clang to output a POSIX-approved polyglot format that runs natively on Linux + Mac + Windows + FreeBSD + OpenBSD + NetBSD + BIOS on AMD64 and ARM64 with the best possible performance.
https://justine.lol/cosmopolitan/
ElectricalUnion · 2023-11-22
> The isolation technology that Flatpak uses (bubblewrap) isn't exclusive to Flatpacked
I wish flatpacked apps actually used the isolation (most don't, so http://flatkill.org/2020/ is still true today) but that isolation is mostly under the control of the packager, not you.
On this point, Deno ( https://docs.deno.com/runtime/manual/basics/permissions ) and pledge.com ( https://justine.lol/pledge ) are better; you have to explicitly allow-list what you want, instead of hoping that the potentially very untrustworthy and third-party packager had your best interests in mind and denylisting what you don't want.
DiggyJohnson · 2023-11-03
Love a great “do you know who you’re dealing with” HN moment.
Justine’s APE [0] project is one of the few things to induce in me true, nostalgic, nerdful glee in the last few years.
[0] https://justine.lol/ape.html
dimator · 2023-04-05
holy cow, her website is enough to give me imposter syndrome https://justine.lol/
jstanley · 2022-10-24
Can we just enjoy the code and not bring politics into it?
> Cosmopolitan Libc makes C a build-once run-anywhere language, like Java, except it doesn't need an interpreter or virtual machine. Instead, it reconfigures stock GCC and Clang to output a POSIX-approved polyglot format that runs natively on Linux + Mac + Windows + FreeBSD + OpenBSD + NetBSD + BIOS with the best possible performance and the tiniest footprint imaginable.
https://justine.lol/cosmopolitan/
grimgrin · 2022-08-17
I wanted to see how this would run in redbean[1], and it runs fantastically!
If you wanna see this in a little executable that you can pass around to your friends, check out this repo I threw up: https://github.com/shmup/redbean-calcpad
This is now essentially an offline CalcPad that still leverages LocalStorage, since the UI is your browser. I've configured this specific build to automatically launch your default browser when you run it.
1. https://justine.lol/redbean2/
DrBazza · 2022-06-16
https://justine.lol/ape.html
One of best technical posts I’ve read in a while.
stephc_int13 · 2022-06-11
The difference between exceptional and average programmers is not something special. It can been seen in all creative fields.
The important factor is not speed but output.
Some people can do things that almost everyone else would consider impossible.
Having even a single one of those in your company can be the most important factor of success.
Fabrice Bellard https://bellard.org/ and Justine Tunney https://justine.lol/ are good examples of this kind of people, but there are of course many others.
mikewarot · 2022-06-07
I think the .COM file was one of the most elegant ways to go. Load the code into a segment at address 100, and start at that address. No parsing, just load and go. It would be interesting to see 32 and 64 bit equivalents.
In the present day, the best, and most creative, format I'm aware of is Actually Portable Executable[1], which is a Windows Portable Execution (PE) file with some added hacks to make a single executable work in a wide variety of places.
[1] - https://justine.lol/ape.html
tomcam · 2022-04-07
The inimitable Justine Tunney, aka jart on HN! See http://justine.lol and be ready to get your mind blown.
Pr0ject217 · 2022-02-07
EDIT:
Paste this hacky snippet into your browser's console to save all of the links into your clipboard:
(() =>
{
let result = [...document.querySelectorAll('td a')]
.map((link) =>
link &&
!link.href.includes('ycombinator') &&
!link.href.includes('javascript:void')
? link.href
: ''
)
.filter(Boolean);
result = [...new Set(result)];
result.sort();
copy(result.join('\n\n'));
})();
Just to help, here's a compiled-list of all of the links shared here so…
posnet · 2021-12-20
If you haven't already, you should check out the C projects from Justine Tunny. Specifically redbean, cosmopolitan libc and ape. https://justine.lol/
Whether you should use them professionally is questionably. But for me they made writing C fun again.
john-tells-all · 2021-11-17
For comparison, I strongly recommend everyone check out Blinkenlights https://justine.lol/blinkenlights/
It's billed as a "debugger"... but it has an entire x86 emulator! The code is very small and clear. Written by national treasure Justine Tunney, of Redbean fame.
I'm considering modifying it to count x86 calls, to trace an executable running, to find hotspots and code that doesn't get called.
andai · 2021-06-17
In case anyone missed it, the Actually Portable Executable is well worth a read:
https://justine.lol/ape.html
https://news.ycombinator.com/item?id=26273960