Updates Apple has made to their operating systems since 2013 have forced us to make some substantial changes under the hood for Airfoil. Most users should notice no differences in their day to day usage of Airfoil. However, these changes are significant, so we've highlighted some differences you might see below.
Airfoil Video Player
Unfortunately, Airfoil Video Player is not fully supported for use on Mavericks and higher.
Instant On
Capturing Audio From Safari, FaceTime, Messages, or QuickTime Player
Due to underlying changes made by Apple, using Airfoil to capture audio from Safari (on Mac OS X 10.9 and up), FaceTime (on Mac OS X 10.10 and up), Messages (on Mac OS X 10.10 and up), or QuickTime Player (on Mac OS X 10.11 and up) now requires the Instant On component. You'll be prompted to install Instant On when capturing audio from these applications.
No Restart Required
Long-time Airfoil users will likely remember that installing and updating the Instant On extra required a restart of the machine. With the latest update, that requirement has been abolished. To install or update Instant On, you need only enter your administrator password. No restart will be required.