This is version 3 of Mac2SDL. It makes the resource fork of a Marathon map file into a [Map File Name].resources file for the SDL players, and it makes a non-resource version of the map (to save slightly on size) and can optionally create a .zip archive out of them and delete the two newly-archived files.
New to version 3 is multiple fille support for drag-n-drop.
A handy tool for those who have merged physics, terminals, scripts, or whatever takes a ride on your map's resource fork. Requires OS X, or maybe Darwin.