NESMaker is Windows only. Will not work on Mac natively.
A solution for mac users, is installing Windows via Bootcamp or via a virtual machine (VirtualBox or Parallel Desktop or VMware...).
As far as I'm aware Joe's never shown footage of NESmaker running on a Mac, all the demonstration footage has been shown using Windows 10 and when the subject comes up he always mentions that he uses bootcamp and runs it under windows. Though it is worth a shot to try it under WINE or even WineBottler and see how it goes. I haven't used MacOSX since the PowerPC and the only unit I have for testing is a G4 Power Mac running Tiger which would be less then helpful. LOL.
It might work under Wine (or WineBottler)... but sincerly, I hate using Wine it's quite ugly, heavy... a pain in the ass. So I use an old Windows7 VM on my mac.
I really would love a native MacOS NESMaker app. One day, maybe.
(Josh, please, rewrite NESMaker in QT )