Dear MacOS X 10.9 mavericks,
RawTherapee 5.4 is due to release very soon. It would be much appreciated if you could test and report any problems you may have running the current development build of RT.
10.9 is the earliest macOS we have tested. This is mainly due to the requirements of the mac ports of some dependent libraries included in the app package. Notably, gtk+3 requires the quartz graphics layer, therefor earlier macOS’ like 10.6 will not work.
Please pick up a copy of dev on this page: