macOS

Show hidden files: Cmd+Shift+.. The . makes sense as in unix parlance hidden files are also known as dot files. I even have my own dotfiles repository to store my personal system configuration.

Cmd+m minimizes a window and then Cmd+Tab does not open it. But if you hide (instead of minimize) with Cmd+h then you can bring it back with Cmd+Tab.

Cmd+Opt+h hides all other windows except the one currently in focus.

Cmd+w closes one instance of a program or tab of a window. Cmd+q closes all the application instances.

Cmd+Spc opens Spotlight. Navigate item by item with up/down and by section (submenus) with Cmd+Up :Cmd+Down. Left-click or press Enter to preview. Cmd+r opens in Finder.

System info: