The missing package manager for macOS or Linux. The script explains what it does and then stops before it does it. Homebrew installs what Apple (or your Linux operating system) did not. Homebrew installs packages in their own directory, then symlinks them into /usr/local (on macOS Intel). Homebrew won’t install files beyond its prefix, so you can place a Homebrew setup wherever you like. Trivially, you can create your own Homebrew packages. It's all Git, Ruby under the hood. So hack away with the knowledge you can easily revert any modifications and merge upstream upgrades. Homebrew formulae can be used as simple Ruby scripts. Homebrew works well with macOS (or any Linux system). Install RubyGems and their dependencies using brew Homebrew Cask installs macOS fonts, plugins, and other non-open-source software. It is as easy as creating a recipe to make a cask.