Hammerspoon is a tool for automating macOS computers, allowing users to write Lua scripts that control applications, windows, the mouse, the keyboard, the screen, wifi and networking, and more. For example, a user could automatically start a set of applications when connecting to a work wifi network and could quit then when connecting to a personal wifi network. Hammerspoon's Getting Started Guide provides a walk-through of creating a basic "Hello World" script. A repository of official modules (called Spoons) can be found at Hammerspoon.org/Spoons. These modules include informational overlays for the desktop or menu bar, modules that manage window layout, application launchers, integrations with various applications, and various others. In addition to the getting started guide, the Hammerspoon wiki on GitHub contains several dozen sample configuration files that new users may examine for inspiration. Hammerspoon is a free software, distributed under the MIT license, with source code available on GitHub.