SuperCal is shareware which means that you can download it and try it out for free, but it will have some features disabled until it is purchased and activated. SuperCal costs US $19 for a single user license which can be easily purchased from within SuperCal.
Please note: When SuperCal is used unlicensed, all measurement and calibration operations will function normally, but the resulting ColorSync profile will be crippled. The profile will be used by the operating system to correct your display's response, but using the profile in ColorSync-aware applications like Photoshop will result in inaccurate colors rendered to any output device. This lets you see the on-screen results of SuperCal's calibration before needing to purchase a license.
Once SuperCal is licensed, you can open any existing profile that you have created and re-save it to repair the profile without having to repeat the measurement process.
To repair a profile created with an unlicensed copy of SuperCal:
To purchase and auto-activate SuperCal, just press the "Unlicensed" button at the bottom of SuperCal's assistant window to open the license window, then press the "Purchase a License" button top open the embedded store. When you are finished checking out, the embedded store will auto-activate SuperCal with your new license information. Don't forget to print a copy of your receipt to save for your records. Tip: Printing to a PDF file is a great way to save your receipt.
If you are an existing registered user of SuperCal that previously purchased through Kagi, you can open the license window and request a new license. Simply enter your information and press the "Request a License" button, and SuperCal will open your default email client and compose a license request message for you. Please double-check the listed name and email address and make sure they are the same ones that you previously used when purchasing SuperCal through Kagi, and send the email when you are done. We will look up your information and send you a new license promptly. Please note that we are doing these by hand, but we will do it as fast as humanly possible :)
If you already have a license, you can simply open the license window and enter your license information, then press the "Activate" button to activate the license.