devenv vs Nix

devenv uses Nix to define development environments for teams and CI. A project configuration can specify packages, languages, services, tasks, secrets, variables, files, and shell scripts. The project lists 58 supported languages and 42 preconfigured services, including PostgreSQL, Redis, MySQL, RabbitMQ, and Elasticsearch. Processes can be supervised with dependencies and restarts, while tasks can run in parallel and integrate with shells or commits. SecretSpec can read declared secrets from sources such as Keychain, 1Password, LastPass, dotenv, and environment variables. devenv can build OCI containers and run integration tests with its processes active; documentation also describes GitHub Actions use for checks, builds, and tests. It requires Nix and works on Linux, macOS, and WSL. As of devenv 2.4, the project no longer builds, tests, or releases it for Intel Macs. Projects must be explicitly trusted before automatic activation. The software is free and MIT licensed, with GitHub and Discord linked for help and community. Cached shell startup is listed as under 100 ms after the first build; devenv Cloud is in private beta.

Nix is a free package management and system configuration tool for creating reproducible, declarative systems. It builds packages in isolation to avoid undeclared dependencies and help keep builds consistent across machines. Users can define and share development and build environments across projects and languages, install software from URLs or source code, and use virtual machines for integration testing. Nix supports dependency resolution, lockfiles, workspaces and offline installation; its package formats include Nix expressions, derivations and flakes. The Nix Packages collection offers over 140,000 packages. The wider ecosystem supports remote builds and deployments, binary caches, cross compilation, atomic upgrades and rollbacks to earlier package versions. Nix runs on Linux and macOS, and on Windows through WSL2; multi-user Windows installation requires WSL systemd support. Documentation includes guides for GitHub Actions, Docker images, Terraform deployment, SSH provisioning and distributed builds. Nix is aimed at people familiar with command-line interfaces and plain-text editors, including developers, test engineers, DevOps engineers, system administrators, data scientists, students and open-source enthusiasts. It has no paid plan listed.