> 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.

That exists: https://github.com/container2wasm/container2wasm

Unfortunately I found the performance to be enough of an issue that I did not look much further into it.

We are working on exactly this: https://browserpod.io

For a full-stack demo see: https://vitedemo.browserpod.io/

To get an idea of our previous work: https://webvm.io

Yeah. Microsoft really went downhill UI-wise.

From the "Technical notes" page:

> Access to Internet is possible inside the emulator. It uses the websocket VPN offered by Benjamin Burns (see his blog). The bandwidth is capped to 40 kB/s and at most two connections are allowed per public IP address. Please don't abuse the service.

https://bellard.org/jslinux/tech.html

Simon, this HN post didn't need to be about Gen AI.

This thing is really inescapable those days.

Check out Jeff Lindsay's Apptron (https://github.com/tractordev/apptron), comes very close to this, and is some great tech all on its own.

Is that even remotely relevant to JSLinux?

https://github.com/copy/v86 might be a more 1:1 fully open sourced alternative.

Parallel thread: https://news.ycombinator.com/item?id=47311484#47312829 - "I've always been fascinated by this, but I have never known what it would be useful for."

I should have replied there instead, my mistake.

Yes, it's one of the available emulated systems on JSLinux.

I use bellard.org/jslinux to test compilation of strange code sometimes[1], since it came with compilers that are different versions from what I have installed locally, and it's easier to open up a browser than starting a VM.

[1] For example:

https://www.ioccc.org/2020/yang/index.html#:~:text=tcc%200.9...

https://www.ioccc.org/2018/yang/index.html#:~:text=tcc%200.9...

I use a similar emulator (v86) as a way to share my hobby OS. Approximately zero people, even my friends, are going to boot my hobby OS on real hardware; I did manage to convince some of them to run it in qemu, but it's difficult. A browser environment shows the thing quite well; and easy networking is cool too.

My hobby OS itself is not very useful, but it's fun if you're in the right mood.

Maybe if you’ve got some ancient software that’s missing source code and only runs with X Y and Z conditions, you could continue to offer it on the web and build around it like that? Not sure if that would be practical at all, but could be interesting

Agentic workloads create and then run code. You don't want to just run that code in a "normal" environment like a container, or even a very well protected VM. There are other options, ofc - eg. gvisor, crossvm, firecracker, etc, but this one is uncommon enough to have a small number of attackers trying to hack it.

Most such emulators have Internet access on the IP level. Therefore, this is a very cheap way to test anything on the Internet.

    apk add nmap
    nmap your.domain.com

However, the speed is heavily throttled. You can even use ssh and login to your own server.

It can also be used as a very cheap way to provide a complete build environment on a single website, for example to teach C/C++. Or to learn the shell. You don't have to install anything.

My college professor used it to teach us the Linux command line

We have Windows PCs in the classroom.

Not really. x86_64 is not supported yet: https://github.com/copy/v86/issues/133

What's wrong with a well protected VM? Especially compared to something where the security selling point is "no one uses it" (according to your argument; I don't know how secure this actually is)

If you'd clicked the link, instead of just reading the title, you'd have known it was.

Wow, thanks for this, this is exactly what v86 was missing! Runs faster than my demo: https://zb3.me/qemu-wasm-test/jspi-noffi/

Even though it has no JIT. Truly magic :)

Nothing, but "there are already working options" does not necessarily mean we shouldn't try new (and sometimes weird) things

Some sort of web based archive of applications/etc where you can boot them up in your browser.

It's getting there. Among other things, it's probably the quickest way to author a Linux environment to embed on the web: https://www.youtube.com/watch?v=aGOHvWArOOE

Apptron uses v86 because its fast. Would love it for somebody to add 64-bit support to v86. However, Apptron is not tied to v86. We could add Bochs like c2w or even JSLinux for 64-bit, I just don't think it will be fast enough to be useful for most.

Apptron is built on Wanix, which is sort of like a Plan9-inspired ... micro hypervisor? Looking forward to a future where it ties different environments/OS's together. https://www.youtube.com/watch?v=kGBeT8lwbo0

That’s what I’d like to use it for as well, but it’s difficult to do so because there’s no way to edit the disk image.

Any advice on how to create a JSLinux clone with a specific file pre-installed and auto-launching would be much appreciated!

Sure, and there are probably some other things lacking, but JSLinux supports a lot more than CLI Linux userspace on x86-64 too. E.g. compare to lack of graphical interface https://github.com/container2wasm/container2wasm/issues/196

It looks like container2wasm uses a forked version of Bochs to get the x86-64 kernel emulation to work. If one pulled that out separately and patched it a bit more to have the remaining feature support it'd probably be the closest overall. Of course one could say the same about patching anything with enough enthusiasm :).

You need backend proxies, the browser doesn't allow ignoring CORS by default.

Similarly I've used it for technical interviews.

Working with VMs always felt difficult because of this. So authoring was built-in to Docker. Now you can use Apptron to author and embed a Linux system on a web page. This aspect is usable, but it's only going to get better.