Install Swift 3: macOS

To use Swift 3 on macOS, you just need to have Xcode 8 installed.

Install Xcode

Install Xcode 8 from the Mac App Store.

After Xcode 8 has been downloaded, you must open it to finish the installation. This may take a while.

Double check the installation was successful by running:

curl -sL check.vapor.sh | bash

You can now move on to Install Toolbox.

Check out Swift.org's extensive guides if you need more detailed instructions for installing Swift 3.0.