Are there any examples of 'perfect' software?
from fortnitefinn@sh.itjust.works to programming@programming.dev on 15 Feb 2026 15:28
https://sh.itjust.works/post/55375651

I’m talking about programs that can’t be improved no matter what. They do exactly what they’re supposed to and will never be changed.

It’ll probably have to be something small, like cd or pwd, but does such a program exist?

#programming

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markz@suppo.fi on 15 Feb 2026 15:31 next collapse

TempleOS

markz@suppo.fi on 15 Feb 2026 15:38 collapse

The dev of left-pad made it perfect by removing it.

bleistift2@sopuli.xyz on 15 Feb 2026 15:34 next collapse

No; since every user defines the perfect program differently. Which should be the default behaviour(s)?

mindbleach@sh.itjust.works on 15 Feb 2026 16:37 next collapse

You cannot criticize a good knife by asking why it’s not a hammer.

bleistift2@sopuli.xyz on 15 Feb 2026 17:00 next collapse

But I can critisize it for having only one sharp edge instead of 2. Or for being too short or too long. Or for having a handle that’s not shaped well for my hand. (That last metaphor is probably the correct one for the sentiment I’m going for.)

mindbleach@sh.itjust.works on 15 Feb 2026 17:17 collapse

The answer remains, this tool is not flawed, it’s just not the one you want.

Vim could be feature-complete and formally verified and I’m still using Xed.

FishFace@piefed.social on 15 Feb 2026 20:29 collapse

A hammer is a completely different tool, but different defaults in a single program are not.

Point is there’s no objective standard for “perfect”

treadful@lemmy.zip on 15 Feb 2026 16:39 collapse

Software is always an ongoing conversation.

mushroommunk@lemmy.today on 15 Feb 2026 15:38 next collapse

I would have said Windows notepad but they screwed the pooch on that one and changed it.

originalucifer@moist.catsweat.com on 15 Feb 2026 15:59 next collapse

notepad++

ieGod@lemmy.zip on 15 Feb 2026 16:13 collapse

They recently experienced an self-update hijack. Plenty of room for improvement.

BlameThePeacock@lemmy.ca on 15 Feb 2026 17:20 collapse

That was a server side compromise, but the update function could have detected it with more security features so you’re still right.

lemmydividebyzero@reddthat.com on 16 Feb 2026 20:33 collapse

Actually had a security vulnerability recently.

pcworld.com/…/windows-notepad-is-now-complex-enou…

panda_abyss@lemmy.ca on 15 Feb 2026 15:42 next collapse

Ski Free

L0rdMathias@sh.itjust.works on 15 Feb 2026 15:43 next collapse

Notepad.exe, pre-windows 11. Now it’s something else entirely but still uses the name :(

edfloreshz@lemmy.ml on 15 Feb 2026 15:48 next collapse

Notepad did what it needed to do, but it could be improved in a lot of ways

FizzyOrange@programming.dev on 15 Feb 2026 15:49 next collapse

Nah it was eternally annoying that it didn’t support Unix line endings. Also there are clearly a ton of basic features that people want from lightweight text editors.

mindbleach@sh.itjust.works on 15 Feb 2026 16:38 next collapse

Notepad in Windows 7 occasionally did some weird shit.

SaveTheTuaHawk@lemmy.ca on 15 Feb 2026 17:27 collapse

I kinda love snipping tool.

[deleted] on 15 Feb 2026 15:47 next collapse
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Bookmeat@lemmy.world on 15 Feb 2026 15:50 next collapse

LaTeX

bleistift2@sopuli.xyz on 15 Feb 2026 15:59 next collapse

Error: Too many unprocessed floats.

SinTan1729@programming.dev on 15 Feb 2026 18:24 next collapse

Not sure about LaTeX, but TeX is widely considered to be almost “perfect” code.

grue@lemmy.world on 15 Feb 2026 21:22 collapse

TeX will be perfect after Knuth dies and the version number is incremented to π.

eager_eagle@lemmy.world on 15 Feb 2026 20:26 collapse

ugh, no way. It might do a fine job with typesetting, but the user experience is utterly awful and that’s very unlikely to change because of design choices over 40+ years. If you don’t think so, give typst a real try.

carmo55@lemmy.zip on 15 Feb 2026 21:04 collapse

Semantic round brackets make typst impossible to use for me. If it had curlies instead it would be great.

FizzyOrange@programming.dev on 15 Feb 2026 15:51 next collapse

Yeah you probably can’t do to much more to pwd or yes or whatever (yeah I know about the silly optimisations). I think once you get much beyond that there are always more features you can add. Even for something like cd, people have made fancier versions with fuzzy matching and so on.

cecilkorik@lemmy.ca on 15 Feb 2026 15:54 next collapse

The flight software for the Apollo moonshots.

dgriffith@aussie.zone on 15 Feb 2026 23:22 next collapse

It was fault tolerant but I wouldn’t say it was perfect. There were plenty of “known issues”, and the fix in production was basically, “don’t do that”.

SlurpingPus@lemmy.world on 16 Feb 2026 11:40 collapse

It’s on Github and has several PRs.

portifornia@piefed.social on 15 Feb 2026 15:58 next collapse

Honestly, it all starts going to shite after “hello world.”

Onomatopoeia@lemmy.cafe on 15 Feb 2026 16:04 next collapse

Hahahahah

homoludens@feddit.org on 15 Feb 2026 16:56 next collapse

Shouldn’t it be “Hello world.”?

thingsiplay@lemmy.ml on 15 Feb 2026 19:16 next collapse

What does perfect hello world even mean? It can be realized in many ways and none is the best way.

degen@midwest.social on 15 Feb 2026 20:45 collapse

Computers can’t even greet you in the real world. Its like some kind of sick joke.

“Dance, clanker! Dance!”

SorteKanin@feddit.dk on 15 Feb 2026 22:17 collapse

No. “Hello, world!” or you’re doing it wrong.

[deleted] on 15 Feb 2026 17:53 collapse
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Onomatopoeia@lemmy.cafe on 15 Feb 2026 16:05 next collapse

Automotive engine control computers.

They just work, for decades and millions of miles.

[deleted] on 15 Feb 2026 16:11 next collapse
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whotookkarl@lemmy.dbzer0.com on 15 Feb 2026 16:19 next collapse

Pretty subjective but if you’re looking for do one thing and do it well I’d go with some of the GNU core utils like you mentioned, vlc & ffmpeg for AV media, and sl for being a silly way to handle ls typos

PoY@lemmygrad.ml on 16 Feb 2026 04:34 collapse

you ever seen vlc on ipad? probably one of the worst apps you can get from the app store

oce@jlai.lu on 15 Feb 2026 16:20 next collapse

You may be interested by this en.wikipedia.org/wiki/Formal_verification.

Prominent examples of verified software systems include the CompCert verified C compiler and the seL4 high-assurance operating system kernel.

lIlIlIlIlIlIl@lemmy.world on 15 Feb 2026 16:50 next collapse

Of course: github.com/kelseyhightower/nocode

theherk@lemmy.world on 15 Feb 2026 17:05 next collapse

Ha. I still have an open PR on that.

BrianTheeBiscuiteer@lemmy.world on 15 Feb 2026 22:06 collapse

Perfect code right here:




ieGod@lemmy.zip on 15 Feb 2026 17:19 next collapse
  • vi
  • grep
  • curl
irelephant@lemmy.dbzer0.com on 15 Feb 2026 22:33 collapse

Ehhh, for curl there is a few features they’re working on (like better websocket support), and I’m sure there’s lots of optimizations that could be made, given how complex a project it is…

entwine@programming.dev on 15 Feb 2026 17:22 next collapse

yes

kibiz0r@midwest.social on 15 Feb 2026 17:34 next collapse

Is there a perfect building?

Probably not, since they exist in an environment — which is constantly changing — and are used by people — whose needs are constantly changing.

The same is true of software. Yes, programs consist of math which has objective qualities. But in order to execute in the physical world, they have to make certain assumptions which can always be invalidated.

Consider fast inverse sqrt: maybe perfect, for the time, for specific uses, on specific hardware? Probably not perfect for today.

KindaABigDyl@programming.dev on 15 Feb 2026 17:43 next collapse

Nope.

I’ve thought about this before, and it gave me an interesting thought process: AI can’t ever be good at doing a large project.

It has a hard limit. Not only is it not as good as us, the best it can ever do is as good as us, and we’re not even good at it. That’s all it can be trained on! Our garbage code lol

ThetaDecay@lemmy.world on 15 Feb 2026 18:00 next collapse

Pkzip version 2.04g

Gork@sopuli.xyz on 15 Feb 2026 18:17 next collapse

WinRAR free version

fruitcantfly@programming.dev on 16 Feb 2026 00:31 collapse

While WinRAR is pretty great, it has also had several severe security vulnerabilities over the years, including one last year:

en.wikipedia.org/wiki/WinRAR#Security

Which isn’t quite what you’d expect from “perfect” software

BrightCandle@lemmy.world on 15 Feb 2026 18:32 next collapse

Pretty certain cd and pwd have changed over the years. The kernel hasn’t remained the same so the commands that use it wont and now we have faster methods to do various things like getting file data the commands that depend on it will change. Less quickly than something that is still gaining features but bit rot is a very real effect since every single part of software is in constant flux.

thingsiplay@lemmy.ml on 15 Feb 2026 19:16 next collapse

I don’t think such thing as perfect software exist, only abandoned software. If the environment changes, then the software needs changes too.

MonkderVierte@lemmy.zip on 15 Feb 2026 20:03 collapse

Or a new software.

thingsiplay@lemmy.ml on 15 Feb 2026 20:18 collapse

Or a rewrite in Rust.

[deleted] on 15 Feb 2026 20:19 collapse
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IanTwenty@piefed.social on 15 Feb 2026 20:15 next collapse

There was a moment in time where maybe it was qmail:

https://en.wikipedia.org/wiki/Qmail

Ten years after the launch of qmail 1.0, and at a time when more than a million of the Internet’s SMTP servers ran either qmail or netqmail, only four known bugs had been found in the qmail 1.0 releases, and no security issues.

More on how it was accomplished:

https://blog.acolyer.org/2018/01/17/some-thoughts-on-security-after-ten-years-of-qmail-1-0/

kalpol@lemmy.ca on 16 Feb 2026 13:26 collapse

Djbdns was excellent too, and ezmlm,.in fact all DJB’s software was quality for its single purpose. The world moved on though, and you had to have your basic Internet servers just…do more

Sephtis@lemmy.world on 15 Feb 2026 20:45 next collapse

Many might disagree, but imo vim is the perfect text editor for a command line interface. It’s just so simpel and does exactly what I need it to do without doing anything unnecessary

karlhungus@lemmy.ca on 15 Feb 2026 20:56 next collapse

neovim is a drop in replacement for vim that fixes the issues that bother me with vim

Sephtis@lemmy.world on 15 Feb 2026 21:12 collapse

Might install that then in the future, if I remember it. Sudo apt-get install vim is just so ingrained in muscle memory

karlhungus@lemmy.ca on 16 Feb 2026 19:35 collapse

not sure why your getting downvoted

Sivecano@lemmy.dbzer0.com on 15 Feb 2026 21:16 next collapse

Vim has some pretty messy design… Starting at some of the action quirks and ending at vim9script

Sephtis@lemmy.world on 15 Feb 2026 21:22 collapse

Never heard of vim9script, what is it. I must admit I don’t use it for a lot of super complicated tasks just regular yaml and file editing. At for that it’s perfect imo

Sivecano@lemmy.dbzer0.com on 16 Feb 2026 10:48 collapse

Vim9-script is a bespoke DSL introduced in vim 9 which was to replace vimscript (the old config language) It was recieved as a bit wacky with its support for classes among other things.

who@feddit.org on 15 Feb 2026 21:35 collapse

Nit: vim is a visual editor. It has a text interface, but it’s not a command line interface.

An example of a command line text editor would be sed.

Sephtis@lemmy.world on 15 Feb 2026 21:58 collapse

I know it isn’t a cli but a text editor that you can use in a terminal, if there’s any other difference i got wrong feel free to correct me

BodePlotHole@lemmy.world on 15 Feb 2026 20:56 next collapse

7zip?

jsnfwlr@lemmy.ml on 16 Feb 2026 08:39 collapse

7zip has had few CVEs and vulnerabilities

kryptonianCodeMonkey@lemmy.world on 15 Feb 2026 21:15 next collapse

Depends on your definition of “perfect” and “improved”. Is it perfect because it does one fundamental thing really well? Is it improved by adding new features?

I think what you’re meaning is, is there a program that is ubiquitous (or at least works anywhere), will basically remain used forever because it does a fundamental job that will always need to be done, and it does that job in the most straightforward way possible that can’t be made any algorithmically simpler, faster, etc. Probably plenty, honestly. Bitwise operations, arithmetic, fetch/store, etc. Though ubiquity/working anywhere gets rarer the higher you go from hardware. Even your suggestion of cd, for example, has to interface with an OS’s file system, of which there are several common types. What it’s doing is simple in concept, but will always be dependent on other programs for the file system.

beeng@discuss.tchncs.de on 15 Feb 2026 21:27 next collapse

Some Quines maybe?

Treczoks@lemmy.world on 15 Feb 2026 22:03 next collapse

TeX. Best documented source, and last bug found was 12 years ago.

fruitcantfly@programming.dev on 16 Feb 2026 00:02 collapse

The 2021 release of Tex included several bug-fixes, so not quite 12 years:

tug.org/texmfbug/tuneup21bugs.html

See also the following list of potential bugs, that may be included in the planned 2029 release of Tex:

tug.org/texmfbug/newbug.html

That said, Tex is still an impressive piece of software

Treczoks@lemmy.world on 16 Feb 2026 06:57 collapse

Thanks for the update, I somehow missed that.

fruitcantfly@programming.dev on 16 Feb 2026 07:46 collapse

To be honest, they didn’t make it easy to find

irelephant@lemmy.dbzer0.com on 15 Feb 2026 22:30 next collapse

wget.

technocrit@lemmy.dbzer0.com on 15 Feb 2026 22:54 next collapse

Logic gates?

fruitcantfly@programming.dev on 16 Feb 2026 00:33 collapse

Logic gates are hardware, not software

ellen@piefed.social on 16 Feb 2026 08:05 next collapse

Winamp! It probably had some bugs or security issues but functional it was perfect imo.

oyo@lemmy.zip on 16 Feb 2026 08:23 next collapse

mcmaster.com is pretty close…

Kissaki@programming.dev on 16 Feb 2026 13:14 collapse

Do you exclude inventory management from that “will never change” so that that’s only about software?

I imagine there will be new products to be listed.

Kolanaki@pawb.social on 16 Feb 2026 08:42 next collapse

A program that just prints “Hello World” to the screen and quits.

Kissaki@programming.dev on 16 Feb 2026 13:12 collapse

…that supports Unicode? Which encodings? Or only ASCII? Unicode continues to change.

I wouldn’t be very confident that it won’t change or offer reasonable opportunities for improvement.

MITM0@lemmy.world on 16 Feb 2026 09:07 next collapse

Does IRC count ?

VitoRobles@lemmy.today on 16 Feb 2026 12:01 next collapse

Didn’t IRC have major insecurity issues?

I can’t remember why IRC died.

vaionko@sopuli.xyz on 17 Feb 2026 07:59 collapse

It never died

Kissaki@programming.dev on 16 Feb 2026 13:15 collapse

The original one? Because there’s numerous extensions to it. I wouldn’t be confident it won’t evolve further.

arcine@jlai.lu on 16 Feb 2026 09:56 next collapse

Idk if it’s perfect but I really like the “literate programming” version of wc

This is not the original, but here is one version of it : github.com/zyedidia/Literate/blob/…/wc.lit

Kissaki@programming.dev on 16 Feb 2026 13:08 collapse

Your sentence abruptly ends in a backtick - did you mean to include something more? Maybe “wc”?

VitoRobles@lemmy.today on 16 Feb 2026 12:05 next collapse

I wanted to say VLC because to me, it’s the gold standard of fully working open-source software that just destroys the commercial competitors.

But it’s not perfect only because society changes. New video formats forces VLC and open-source devs to adapt. Bigger video and new tech specs require VLC to update. If it wasn’t for all those external needs, VLC would be perfect.

Did I also mentioned the many times rich companies wanted to buy VLC and they laughed?

luridness@lemmy.ml on 17 Feb 2026 04:50 collapse

Personally I prefer MPV but yeah both just wrap around FFMPEG

WolfLink@sh.itjust.works on 17 Feb 2026 06:33 collapse

It’s worth noting that most commercial multimedia software is also more or less a wrapper around ffmpeg

thatsnomayo@lemmy.ml on 16 Feb 2026 13:13 next collapse

emacs can only be improved no matter what but it should count

ExperimentalGuy@programming.dev on 16 Feb 2026 18:47 collapse

As a vim user, I agree that it can only be improved.

kalpol@lemmy.ca on 16 Feb 2026 13:25 next collapse

Htop

arthur@lemmy.zip on 17 Feb 2026 04:37 collapse

Btop?

Kissaki@programming.dev on 16 Feb 2026 13:30 next collapse

For software to be perfect, can not be improved no matter what, you’d have to define a very specific and narrow scope and evaluate against that.

Environments change, text and data encoding and content changes, forms and protocol of input and output changes, opportunities and wishes to integrate or extend change.

pwd seems simple enough. cd I would already say no, with opportunities to remember folders, support globbing, fuzzy matching, history, virtual filesystems. Many of those depend on the environment you’re in. Typically, shells handle globbing. There’s alternative cd tools that do fuzzy matching and history, and virtual filesystems are usually abstracted away. But things change. And I would certainly like an interactive and fuzzy cd.

Now, if you define it’s scope, you can say: “All that other stuff is out of scope. It’s perfect within it’s defined target scope.” But I don’t know if that’s what you’re looking for? It certainly doesn’t mean it can’t be improved no matter what.

ne0phyte@feddit.org on 16 Feb 2026 15:50 collapse

If you just need the functionality then fzf does (among other things) exactly that. Interactive fuzzy cd. If you use the shell bindings you can do cd foo/bar/**<tab> to get a recursive fuzzy matching or you can do alt+c to immediately find any subdirectory and directly cd into it upon pressing enter. You can also use Ctrl+T to find and insert a path into the prompt.

Kissaki@programming.dev on 17 Feb 2026 12:15 collapse

Thanks for the suggestion. As a first step, I set it up in Nushell with a ctrl+t shortcut:

$env.config.keybindings = (
    $env.config.keybindings | append {
        name: fzf_file_picker
        modifier: control
        keycode: char_t
        mode: [emacs, vi_insert, vi_normal]
        event: {
            send: ExecuteHostCommand
            cmd: "commandline edit --insert (fzf | str trim)"
        }
    }
)

Maybe I will look into more. :) I’ve known about fzf but I guess never gotten around to fully evaluating and integrating it.

Nushell supports fuzzy completions, globbing, and “menus” (TUI) natively. Still, the TUI aspect and possibly other forms of integrations seem like they could be worthwhile or useful as extensions.

Blackmist@feddit.uk on 16 Feb 2026 16:26 next collapse

TeX?

Development is considered to be complete, and the version numbering is just adding a digit of pi. Last change was 5 years ago.

ehxor@lemmy.ca on 17 Feb 2026 21:51 collapse

This was going to be my point. The idea that as the software slowly makes new releases the version number more and more closely approximates Pi

somegeek@programming.dev on 16 Feb 2026 20:00 next collapse

I would say git, tex, sqlite, Clojure, Steel banks common lisp are some of the candidates.

Perfect doesn’t meen “not any bugs fixes or features needed” to me. I can’t really define what it means to me…

lemmydividebyzero@reddthat.com on 16 Feb 2026 20:30 next collapse

Windows event viewer… You open it, go to the toilet, to the shower, take a coffee, … and only 2 more minutes later, it shows you the entries…

It’s so perfect, they never had to improve it in decades.

/s

thedeadwalking4242@lemmy.world on 16 Feb 2026 21:21 next collapse

Anything I’ve ever written…

…JK I suck ass

padreati@lemmy.zip on 16 Feb 2026 21:40 next collapse

Some time ago I used haproxy, a software load balancer. I remember that I found an issue which was that it could start with an empty configuration or something similar. When I reached the owner repo it was stated that there were found nu bugs for years of heavy use.

[deleted] on 17 Feb 2026 05:18 next collapse
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antimidas@sopuli.xyz on 17 Feb 2026 07:20 next collapse

Ed. It’s the standard text editor.

www.gnu.org/fun/jokes/ed-msg.html

SlIdE42@jlai.lu on 15 Mar 12:38 collapse

Ericsson’s AXD 301 has achieved a NINE nines reliability (yes, you read that right, 99.9999999%)!