Homebrew

Homebrew is the package manager that made macOS usable for developers. Before Homebrew, installing developer tools on Mac meant hunting for DMGs or compiling from source. Now it's "brew install" and move on with your life.

If you're on macOS, you're probably already using it. There's no real competition in its niche — MacPorts is the legacy alternative with less community momentum. Nix is the technically superior option with reproducible builds, but the learning curve is brutal. On Linux, your distro's package manager (apt, dnf) handles the job, though Homebrew works on Linux too.

The formula ecosystem is massive, the cask system handles GUI apps elegantly, and updates are a single command. It just works, which is the highest compliment for infrastructure tooling.

The catch: Homebrew installs everything into a shared prefix, so version conflicts happen. It's opinionated about where things go and how they're linked. And if you need reproducible, pinned environments, Homebrew wasn't designed for that — look at Nix or Docker instead.