The Complete Guide to Package Managers — How npm, uv, RPM, and Homebrew Work and How to Publish Software

{
  "name": "my-project",
  "version": "1.0.0",
  "dependencies": {
    "express": "^4.18.0",
    "lodash": "~4.17.21"
  },
  "devDependencies": {
    "jest": "^29.0.0"
  }
}

{
  "name": "my-project",
  "lockfileVersion": 3,
  "packages": {
    "node_modules/express": {
      "version": "4.18.2",
      "resolved": "https://registry.npmjs.org/express/-/express-4.18.2.tgz",
      "integrity": "sha512-abc123..."
    }
  }
}

~/.pnpm-store/
  v3/
    files/
      ab/cdef1234...   # actual files of lodash 4.17.21

project-a/node_modules/.pnpm/
  lodash@4.17.21/
    node_modules/
      lodash/
        index.js  -->  ~/.pnpm-store/v3/files/ab/cdef1234... (hard link)

npm adduser
# or if you already have an account
npm login

mkdir my-awesome-lib
cd my-awesome-lib
npm init

{
  "name": "my-awesome-lib",
  "version": "1.0.0",
  "description": "A library that does awesome things",
  "main": "dist/index.js",
  "types": "dist/index.d.ts",
  "files": ["dist"],
  "scripts": {
    "build": "tsc",
    "prepublishOnly": "npm run build"
  },
  "keywords": ["awesome", "utility"],
  "author": "Your Name",
  "license": "MIT",
  "repository": {
    "type": "git",
    "url": "https://github.com/yourname/my-awesome-lib"
  }
}

# Verify the build
npm run build

# Preview before publishing (check which files are included)
npm pack --dry-run

# Actually publish
npm publish

# For scoped packages (public)
npm publish --access public

# Bump patch version (1.0.0 -> 1.0.1)
npm version patch

# Bump minor version (1.0.1 -> 1.1.0)
npm version minor

# Bump major version (1.1.0 -> 2.0.0)
npm version major

# Publish
npm publish

# Install uv
curl -LsSf https://astral.sh/uv/install.sh | sh

# Create a project
uv init my-project
cd my-project

# Add dependencies
uv add requests flask

# Sync dependencies (based on lock file)
uv sync

# Installing requests + flask + sqlalchemy (cold cache)
pip install:    12.4s
poetry install:  8.1s
uv sync:         0.8s   # 15x faster

Example: A>=1.0 requires B>=2.0, but C<1.5 requires B<2.0
  -> Conflict detected
  -> Learned: A>=1.0 AND C<1.5 cannot hold simultaneously
  -> Backtrack and try different versions

[build-system]
requires = ["hatchling"]
build-backend = "hatchling.build"

[project]
name = "my-python-lib"
version = "1.0.0"
description = "A useful Python library"
readme = "README.md"
requires-python = ">=3.9"
license = "MIT"
authors = [
    { name = "Your Name", email = "you@example.com" }
]
dependencies = [
    "requests>=2.28.0",
    "pydantic>=2.0",
]

[project.urls]
Homepage = "https://github.com/yourname/my-python-lib"
Documentation = "https://my-python-lib.readthedocs.io"

[project.optional-dependencies]
dev = ["pytest", "ruff", "mypy"]

# Install build tools
uv add --dev build

# Run the build
python -m build

# .whl and .tar.gz files are created in the dist/ directory
ls dist/
# my_python_lib-1.0.0-py3-none-any.whl
# my_python_lib-1.0.0.tar.gz

# Install twine
uv add --dev twine

# Upload to TestPyPI
python -m twine upload --repository testpypi dist/*

# Test installation
pip install --index-url https://test.pypi.org/simple/ my-python-lib

# Upload to PyPI
python -m twine upload dist/*

# Now anyone can install it
pip install my-python-lib
# or
uv add my-python-lib

name: Publish to PyPI
on:
  release:
    types: [published]

jobs:
  publish:
    runs-on: ubuntu-latest
    permissions:
      id-token: write
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-python@v5
        with:
          python-version: "3.12"
      - run: pip install build
      - run: python -m build
      - uses: pypa/gh-action-pypi-publish@release/v1

# Direct RPM usage (no automatic dependency resolution)
rpm -ivh package-1.0.0-1.el9.x86_64.rpm

# Using dnf (automatic dependency resolution)
dnf install nginx

# Query package info
rpm -qi nginx

# List files in a package
rpm -ql nginx

# Install build tools
dnf install rpm-build rpmdevtools

# Create the build directory structure
rpmdev-setuptree

# The resulting structure:
# ~/rpmbuild/
#   BUILD/      - where builds are performed
#   RPMS/       - built RPM files
#   SOURCES/    - source tarballs
#   SPECS/      - spec files
#   SRPMS/      - source RPM files

Name:           myapp
Version:        1.0.0
Release:        1%{?dist}
Summary:        My awesome application

License:        MIT
URL:            https://github.com/yourname/myapp
Source0:        %{name}-%{version}.tar.gz

BuildRequires:  gcc
BuildRequires:  make
Requires:       openssl-libs

%description
MyApp is an awesome application that does useful things.
It supports multiple platforms and is easy to configure.

%prep
%autosetup

%build
%configure
%make_build

%install
%make_install

%files
%license LICENSE
%doc README.md
%{_bindir}/myapp
%{_mandir}/man1/myapp.1*
%config(noreplace) %{_sysconfdir}/myapp.conf

%changelog
* Sat Apr 12 2026 Your Name <you@example.com> - 1.0.0-1
- Initial package

# Copy source tarball to SOURCES
cp myapp-1.0.0.tar.gz ~/rpmbuild/SOURCES/

# Build RPM (-ba: both binary and source RPM)
rpmbuild -ba ~/rpmbuild/SPECS/myapp.spec

# Check the built RPM
ls ~/rpmbuild/RPMS/x86_64/
# myapp-1.0.0-1.el9.x86_64.rpm

# Install createrepo
dnf install createrepo_c

# Create the repo directory
mkdir -p /var/www/html/myrepo/

# Copy RPMs
cp ~/rpmbuild/RPMS/x86_64/myapp-*.rpm /var/www/html/myrepo/

# Generate repo metadata
createrepo /var/www/html/myrepo/

# /etc/yum.repos.d/myrepo.repo
[myrepo]
name=My Custom Repository
baseurl=http://myserver.example.com/myrepo/
enabled=1
gpgcheck=0

# Install a package
brew install wget

# Check the install path
brew --prefix wget
# /opt/homebrew/opt/wget

# Cellar internal structure
ls /opt/homebrew/Cellar/wget/1.21.4/
# bin/  etc/  share/

# Force-link a keg-only package
brew link --force openssl@3

# Formula/myapp.rb
class Myapp < Formula
  desc "My awesome command-line application"
  homepage "https://github.com/yourname/myapp"
  url "https://github.com/yourname/myapp/archive/refs/tags/v1.0.0.tar.gz"
  sha256 "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
  license "MIT"

  depends_on "go" => :build

  def install
    system "go", "build", *std_go_args(ldflags: "-s -w -X main.version=#{version}")
  end

  test do
    assert_match "myapp version #{version}", shell_output("#{bin}/myapp --version")
  end
end

# Add the Tap
brew tap yourname/mytap

# Install
brew install yourname/mytap/myapp

# Or, after adding the Tap, install directly
brew install myapp

# Clone homebrew-core and add a Formula
brew tap --force homebrew/core
cd $(brew --repository homebrew/core)

# Formula creation helper
brew create https://github.com/yourname/myapp/archive/refs/tags/v1.0.0.tar.gz

# Validate the Formula
brew audit --new myapp
brew test myapp

# Submit PR (GitHub CLI)
gh pr create --title "myapp 1.0.0 (new formula)" --body "Description of the tool..."

# Casks/myguiapp.rb
cask "myguiapp" do
  version "2.1.0"
  sha256 "abc123def456..."

  url "https://github.com/yourname/myguiapp/releases/download/v#{version}/MyGuiApp-#{version}.dmg"
  name "MyGuiApp"
  desc "A beautiful GUI application"
  homepage "https://myguiapp.example.com"

  app "MyGuiApp.app"

  zap trash: [
    "~/Library/Application Support/MyGuiApp",
    "~/Library/Preferences/com.yourname.myguiapp.plist",
  ]
end

# Install a Cask
brew install --cask myguiapp

class ComplexApp < Formula
  desc "A complex application with many build options"
  homepage "https://complexapp.dev"

  # Stable version source
  url "https://github.com/yourname/complexapp/archive/refs/tags/v2.0.0.tar.gz"
  sha256 "deadbeef..."

  # HEAD version (in development)
  head "https://github.com/yourname/complexapp.git", branch: "main"

  license "Apache-2.0"

  # Build dependencies
  depends_on "cmake" => :build
  depends_on "pkg-config" => :build

  # Runtime dependencies
  depends_on "openssl@3"
  depends_on "sqlite"

  # Platform restriction
  depends_on :macos

  def install
    args = %W[
      --prefix=#{prefix}
      --with-openssl=#{Formula["openssl@3"].opt_prefix}
      --with-sqlite=#{Formula["sqlite"].opt_prefix}
    ]

    system "./configure", *args
    system "make", "install"

    # Install shell completions
    bash_completion.install "completions/complexapp.bash"
    zsh_completion.install "completions/_complexapp"
    fish_completion.install "completions/complexapp.fish"
  end

  # Post-install message
  def caveats
    <<~EOS
      To start complexapp as a service:
        brew services start complexapp
    EOS
  end

  # Installation verification test
  test do
    assert_match version.to_s, shell_output("#{bin}/complexapp --version")
    system "#{bin}/complexapp", "check"
  end
end