1. Download Wine Staging. New Link

2. Install Wine.

3. Download & Install AVR Studio 4.18 AND AVR Studio 4.18 SP2. New Link

4. Open AVRStudio.exe (mine was in /Users/Gene/.wine/drive_c/Program Files/Atmel/AVR Tools/AvrStudio4).

5. New project, type AVR GCC.

6. Debug platform: I chose AVR Simulator and ATmega324PA.

7. While coding, I saved and used "build" to generate a .hex file in a folder named "default" one level above the .c file.