Update:
04JAN2015
Follow this link for an updated Registax wrapper and a completely new AutoStakkert wrapper with preinstalled ffmpeg!
Original post below.
Registax 6.1.0.8 is working for me in OSX Mavericks 10.9.1. This is achieved by downloading Wineskin Winery and using it to package Registax in a emulated environment. Everything appears to be functional with the exception that the drop down menu in the “Open file(s)” dialog is broken (files can still be opened). You can use the links above to package Registax so that will work in OSX, or you can download the prepackaged Registax I’ve linked below.
Registax 6.1.0.8 packaged in Wine for OSX Mavericks.