Simon Willison’s Weblog

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10th September 2026 - Link Blog

Any Nix package, live in your browser (via) Farid Zakaria calls this his "magnum opus of Nix work", and I can see why.

trynix.dev provides a qemu-wasm powered x86_64 Linux virtual machine running entirely in your browser through WebAssembly. That VM can then be booted with any Nix package from the past 13 years. They are URL addressable, so you can navigate to this page:

https://trynix.dev/?pkg=python3%403.6.2

Then click "Load" and get an interactive shell against a virtual machine running Python 3.6.2 from 2017.

Farid is building all sorts of neat things on top of this. One recent example: Review a pull request by booting it introduces trynix-preview, described like this:

GitHub action that comments a link on a pull request which lets you boot the PR’s build in the browser using https://trynix.dev. No servers, just browsers.

This is a link post by Simon Willison, posted on 10th September 2026.

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