I've analyzed the provided text and identified several key points:

1. Close App: The Close app for Mac/Windows allows users to make calls, but requires a native application installation. It also has features that can be updated.

2. Dropbox Business Team Spaces SFTP: The rsa-sha2-512 and rsa-sha-256 algorithms are now supported in Dropbox Business Team Spaces SFTP.

3. Closing all windows on Mac: Users can close all windows on a Mac computer using a keyboard shortcut or by navigating to the top toolbar in Safari.

4. Developing cross-platform websites and services: Developments can be done on Linux, macOS, or Windows to build cross-platform websites and services.

5. Legacy macOS versions: It's possible to download older versions of OS X (10.4-11) using online or offline methods, including disk images.

Regarding your key, I understand you're looking for instructions on how to 'Close All Windows' specifically for Mac. According to the provided text, one way to do this is by navigating to the top toolbar in Safari or using a keyboard shortcut.

For mac download Close All Windows 5.8