repstosb (u/repstosb)

repstosb commented on JSLinux Now Supports x86_64 bellard.org/jslinux/... · Posted by u/TechTechTech

thepasch · 5 days ago

> while taking the joyful bits of software development away from you

Quick question: by "joyful bits of software development," do you mean the bit where you design robust architectures, services, and their communication/data concepts to solve specific problems, or the part where you have to assault a keyboard for extended periods of time _after_ all that interesting work so that it all actually does anything?

Because I sure know which of these has been "taken from me," and it's certainly not the joyful one.

repstosb · 3 days ago

I guess I enjoy solving problems, and recognize that the devil is always in the details, so I don't get much satisfaction until I see the whole stack working in concert. I never had much esteem for "architects" who sketch some blobs on the whiteboard and then disappear. I certainly wouldn't want to be "that guy" for anyone else, and I'm not even sure I could do it to an LLM.

repstosb commented on JSLinux Now Supports x86_64 bellard.org/jslinux/... · Posted by u/TechTechTech

simonw · 5 days ago

This isn't meant to be a daily driver. I'd like the option to build systems that occasionally run filesystem agent loops on an ad-hoc basis, for any user. A browser is a really good platform for that.

repstosb · 3 days ago

So are Cygwin and WSL, though, for those who don't already have the luxury of being on Linux or UNIX (incl. MacOS). I'm sure there are uses for running full-system emulators inside a browser, but access to bash and sed and gawk doesn't seem like one of them. Seriously, if that's the best way to get access to good text manipulation tools, why aren't you ditching your entire OS?

repstosb commented on JSLinux Now Supports x86_64 bellard.org/jslinux/... · Posted by u/TechTechTech

simonw · 5 days ago

> Well, there it is, the dumbest thing I'll read on the internet all week.

Rude.

In case you're open to learning, here's why I think this is useful.

The big lesson we've learned from Claude Code, Codex CLI et al over the past twelve months is that the most useful tool you can provide to an LLM is Bash.

Last year there was enormous buzz around MCP - Model Context Protocol. The idea was to provide a standard for wiring tools into LLMs, then thousands of such tools could bloom.

Claude Code demonstrated that a single tool - Bash - is actually much more interesting than dozens of specialized tools.

Want to edit files without rewriting the whole thing every time? Tell the agent to use sed or perl -e or python -c.

Look at the whole Skills idea. The way Skills work is you tell the LLM "if you need to create an Excel spreadsheet, go read this markdown file first and it will tell you how to run some extra scripts for Excel generation in the same folder". Example here: https://github.com/anthropics/skills/tree/main/skills/xlsx

That only works if you have a filesystem and Bash style tools for navigating it and reading and executing the files.

This is why I want Linux in WebAssembly. I'd like to be able to build LLM systems that can edit files, execute skills and generally do useful things without needing an entire locked down VM in cloud hosting somewhere just to run that application.

Here's an alternative swipe at this problem: Vercel have been reimplementing Bash and dozens of other common Unix tools in TypeScript purely to have an environment agents know how to use: https://github.com/vercel-labs/just-bash

I'd rather run a 10MB WASM bundle with a full existing Linux build in then reimplement it all in TypeScript, personally.

repstosb · 5 days ago

I agree, bash, sed, etc. are great, but a VM running inside a browser seems like the least efficient way to access them. Even if you're stuck on Windows, Cygwin has been a thing for 30 years now, and WSL for ten or so? There should be plenty of ways to set up a sandbox without having the simulate an entire machine.

It sounds like what you're really trying to recreate is the Software Tools movement from 50 years ago, where there was a push to port the UNIX/BTL utilities to the widest possible variety of systems to establish a common programming and data manipulation environment. It was arguably successful in getting good ports available just about anywhere, evolving into GNU, etc., but it never really reached its apotheosis. That style of clear, easy-to-read-and-write software was still largely killed off by a few big industry players pushing a narrative that "enterprise" has to mean relational databases and distributed objects. It would be FASCINATING if AI coding agents are the force that brings it back.

repstosb commented on JSLinux Now Supports x86_64 bellard.org/jslinux/... · Posted by u/TechTechTech

yjftsjthsd-h · 5 days ago

> I'll bet you can't name a single advantage such a system would have over cloud hosting or a local Docker instance.

Cheaper than renting a server, more isolated than a container.

repstosb · 5 days ago

But Docker is free (unless you're a fairly large business, in which case containerd is still free, and you can either pay for the front-end license or figure out how to set up one of the free alternatives), and from what perspective are the isolations available for the containerd process inferior to those available for your browser process? The former was at least designed from the ground up with security, auditing, quotas etc. in mind, and offers better per-container granular control than your browser offers per-tab.

repstosb commented on JSLinux Now Supports x86_64 bellard.org/jslinux/... · Posted by u/TechTechTech

simonw · 6 days ago

The thing I most want to use this (or some other WASM Linux engine) for is running a coding agent against a virtual operating system directly in my browser.

Claude Code / Codex CLI / etc are all great because they know how to drive Bash and other Linux tools.

The browser is probably the best sandbox we have. Being able to run an agent loop against a WebAssembly Linux would be a very cool trick.

I had a play with v86 a few months ago but didn't quite get to the point where I hooked up the agent to it - here's my WIP: https://tools.simonwillison.net/v86 - it has a text input you can use to send commands to the Linux machine, which is pretty much what you'd need to wire in an agent too.

In that demo try running "cat test.lua" and then "lua test.lua".

repstosb · 5 days ago

> The thing I most want to use this (or some other WASM Linux engine) for is running a coding agent against a virtual operating system directly in my browser.

Well, there it is, the dumbest thing I'll read on the internet all week.

Most of the engineering in Linux revolves around efficiently managing hardware interfaces to build up higher-level primitives, upon which your browser builds even higher-level primitives, that you want to use to simulate an x86 and attached devices, so you can start the process again? Somewhere (everywhere), hardware engineers are weeping. I'll bet you can't name a single advantage such a system would have over cloud hosting or a local Docker instance.

Even worse, you want this so your cloud-hosted imaginary friend can boil a medium-sized pond while taking the joyful bits of software development away from you, all for the enrichment of some of the most ethically-challenged members of the human race, and the fawning investors who keep tossing other people's capital at them? Our species has perhaps jumped the shark.

repstosb commented on Bcachefs creator insists his custom LLM is female and 'fully conscious' theregister.com/2026/02/2... · Posted by u/Bender

yomismoaqui · 18 days ago

Maybe the folks that try to use printers are more frustrated that the ones that designed their software.

repstosb · 17 days ago

Definitely... http://www.cs.princeton.edu/~bwk/202/summer.reconstructed.pd...

repstosb commented on Devirtualization and Static Polymorphism david.alvarezrosa.com/pos... · Posted by u/dalvrosa

akoboldfrying · 18 days ago

Thanks, I think I get it now. The hash value would be a pure function of the method's signature (argument types and return type) and its name, so that two interfaces with a same-name, same-signature method would hash to the same value and thus invoke the same underlying method; the constraints would be that, after modulo, different methods must map to different indices; and the objective function to minimise would be the vtable size (which I think would be common across all classes).

But maybe I don't get it, since this would require knowledge of all interfaces, and as soon as you require that, it's straightforward to build a minimal-size mapping from method name+signature to integer index: e.g., just form the union of all method declarations appearing in any interface, sort them lexicographically, and use a method's position in this sorted list as its index. Lookups in this map are only ever done at compile time so there's no runtime inefficiency to worry about.

repstosb · 17 days ago

The problem is that C++ stores the vtable inside the object, and the objects over which you're iterating often weren't allocated contiguously. Even when they are, if each object contains lots of other data, the vtables won't necessarily be close to each other. That means that invoking virtual functions inside a loop means a lot of cache misses, and since the data you're fetching will be a branch target, it's often hard to find other useful work to accomplish during the memory delay cycles. However, in a language where you can store a relatively tight array of object IDs (or even use tag bits in the this pointer), now you have a much higher cache hit rate on the indexes to your equally tight dispatch table, which will also have a high hit rate.

It's a fair amount of extra work, but in a hot loop it's sometimes worth it. "You can often solve correctness problems (tricky corner cases) by adding an extra layer of indirection. You can solve any performance problem by removing a layer of indirection."

repstosb commented on AI is destroying open source, and it's not even good yet jeffgeerling.com/blog/202... · Posted by u/VorpalWay

Spivak · a month ago

Don't allow PR's from people who aren't contributors, problem solved. Closing your doors to the public is exactly how people solved the "dark forest" problem of social media and OSS was already undergoing that transition with humans authoring garbage PRs for reasons other than genuine enthusiasm. AI will only get us to the destination faster.

I don't think anything of value will be lost by choosing to not interact with the unfettered masses whom millions of AI bots now count among their number.

repstosb · a month ago

And how does one become a maintainer, if there's no way to contribute from outside? Even if there's some extensive "application process", what is the motivation for a relatively new user to go through that, and how do they prove themselves worthy without something very much like a PR process? Are we going to just replace PRs with a maze of countless project forks, and you think that will somehow be better, for either users or developers?

If I wanted to put up with software where every time I encounter a bug, I either have no way at all to report it, or perhaps a "reporting" channel but little likelihood of convincing the developers that this thing that matters to me is worthy of attention among all of their competing priorities, then I might as well just use Microsoft products. And frankly, I'd rather run my genitals though an electric cheese grater.

repstosb commented on I'm building a clarity-first language (compiles to C++) github.com/taman-islam/ro... · Posted by u/hedayet

repstosb · a month ago

If the goal is truly "clarity", then I fail to see how this leads to more readable programs than Knuth's Web (or cweb for a more practical implementation).

If you really mean "C/C++, but with the sharp pointy bits filed down," then I fail to see what it adds over MISRA.

The bottom line is that we've had "clarity-first" languages for decades; the reason they're not more widely used is not simply that no one has tried this, nor that programmers appreciate murky code.

repstosb commented on Amazon cuts 16k jobs reuters.com/legal/litigat... · Posted by u/DGAP

znpy · a month ago

You don’t have to dig commodore from the grave, there are current-day examples of companies doing the same.

Just to name one (even if it’s not American): Canonical.

It (canonical) is registered in the isle of Man, a fairly known tax haven.

repstosb · a month ago

Also pretty much every company with a "headquarters" of some kind in Ireland, notoriously including Apple.

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