What problem does it solve? Setting up project dependencies and language runtimes manually with shell commands like npm install, pip install, or apt install is error-prone, especially in Nix-based environments where package names differ from apt conventions. This Skill provides structured functions to install and remove language packages, system dependencies, and language runtimes correctly. ## Core Features & Use Cases - Language Runtime Management: List available language toolchains and install or remove runtimes like Python 3.11 or Node.js 20. - Package Installation: Install and uninstall language-specific packages for Node.js, Python, Bun, Go, and Rust, with automatic updates to package.json or requirements.txt. - System Dependencies via Nix: Install OS-level tools like ffmpeg, jq, and imagemagick using correct Nixpkgs attribute paths. - Use Case: When setting up a Flask project, install the Python runtime, add flask and gunicorn packages, and install system libraries like cairo for native dependencies, all through validated function calls. ## Quick Start Install the Python 3.11 runtime and the flask and requests packages for my project.