LixCon 2026

Regiux: prototyping a fast Nix interpreter
2026-04-17 , Amphitheater Dussane

The Nix expression language is challenging to evaluate due to non-strict semantics, dynamic scoping, a diverse collection of builtin operators, and tight integration with the Nix store. We give a progress report on Regiux, an interpreter for Nix which is narrowly focused on efficient evaluation of expressions.


Regiux is yet another attempt at a fast Nix evaluator. Come learn about the ingredients that go into modern compilers and interpreters, particularly:

  • Lexing and parsing
  • Desugaring and expanding
  • Intermediate languages for lambda calculus
  • Using the RPython JIT toolkit
  • Bytecode for lazy graph evaluation
See also:

Corbin Simpson is a logician from Oregon. His interests include jazz piano, speedrunning, compiler engineering, site reliability engineering, and information security. Corbin has been a NixOS contributor for about a decade.