Checkout: Mac 10.9 Mavericks Compatibility
Checkout version 3.6 has been tested on Mac OS X 10.9 (Mavericks) and is compatible. If you are currently running Checkout on Mac OS X 10.6 or later, you'll be prompted to update to Checkout 3.6. Checkout 3.6 is required in order to run Checkout on Mac OS X 10.9.
In order to support the new operating system, Mac OS X 10.5 support has been removed. If you are using Mac OS X 10.5, do not install this update.