iTerm2

iTerm2 has been the default answer to "which terminal" on the Mac for about fifteen years, and it has never asked for money. It is GPL v2, the source is on GitHub, and the only payment path on the site is a donation button you can ignore.

The reason people install it over Terminal.app is the accumulated small things. Split a pane and keep both halves searchable. Hit a global hotkey and a terminal drops down over whatever app you were in, then disappears again. Search scrollback with a regex, or replay what scrolled past. Install the shell integration and the app starts tracking where each command began and ended, what it exited with, and which directory you were in, which makes scrolling back through a long session far less of a hunt. Triggers can watch output and act on a match: highlight a line, fire a notification, stop a runaway.

The cost of fifteen years of features is weight. Dump a hundred thousand lines into it and you will feel the difference against Ghostty or Alacritty, and the preferences window is genuinely intimidating on first open.

If you only touch a shell to run the occasional build, Terminal.app is fine and already installed. iTerm2 pays off when the terminal is where you work.