finix - an experimental os, featuring finit as pid 1, to explore the NixOS design space (nixcon2025)

NixOS is a remarkably flexible and powerful operating system, but its stability and scale can make it a challenging environment for exploring unconventional ideas. finix is an experimental Nix-based OS I built to break free from some of the constraints of upstream NixOS — a fully functional, Nix-built system that embraces rapid and bold experimentation over stability. This talk will walk through how I built finix, how I reuse much of NixOS’s scaffolding, and why I chose to try a different init system, finit. But more than the implementation details, I want to share how having a small, purpose-built codebase has created space to rapidly prototype ideas — like alternative service frameworks or minimal module sets — and see what works. finix isn’t meant to replace anything, but it could serve as a useful place to explore concepts that might one day feed back into the broader NixOS ecosystem, or at least help us think differently about how it’s designed. Beyond finix itself, I’d like to use this talk to advocate for a more diverse ecosystem of sibling projects in the Nix community — especially to better support efforts like the Nix-based BSD project. Valuable ideas don’t always need to go upstream to have an impact. Though built for experimentation, I run finix as my daily driver — and on my laptop, it’s just as smooth and capable as NixOS. That reliability makes it a practical foundation for trying out new ideas in real-world use, and it’s convinced me that we need more room for experiments like this — and more space for alternative perspectives in our community. about this event: https://talks.nixcon.org/nixcon-2025/talk/Q8VUKL/