Hi, how does it work the file-builder on macOS? Because I can't actually open it and if I'm not mistaken I need it before starting to work on QuickNII. I downloaded the first package at this link https://www.nitrc.org/frs/?group_id=1341... Maybe I'm missing something obvious. 
Thanks in advance

Hi,
Assuming the issue is a security message offering Cancel and Eject options only, that can be overcome via visiting the Apple menu, opening "System Preferences...", and picking "Security & Privacy" from the View menu. There the General tab will list QuickNII as an unverified application, and its running can be allowed manually.