How to Download 7Zip on MAC? Official Site

Do you know how to open it?


Credits:

[darrenhenson]

1. Attempt to open the file so there is a current instance for the Mac to know about. 
2. Go to your computer's System Preferences. 
3. Select Security & Privacy. 
4. Click the lock, and then under the General tab, there will be a button that says Open Anyway. Click it.

[geneaso]

For future viewers, this 7zz file is a binary/application you use on terminal. It doesn't have any GUI (Graphical User Interface) unlike in Windows. Basically you use it using terminal and use its commands to extract/delete/modify your compressed files.