Help Window
You're looking at it. This displays the Airfoil Manual, and can be accessed by pressing Command-? or choosing 'Airfoil Manual' from the Help menu.
Registration Window
As seen above. Click 'Enter License' to enter a license for Airfoil, which may be purchased from our store, then click Print to make a copy for safekeeping. If you don't own a license, click Buy to purchase a code. If you've lost your license, click the 'I Lost My License' button.
About Window
Displays the credits for Airfoil.