Hi Chris,
This certainly sounds promising. I have a question...
Instead of using {$linklib} directive shouldn't it also work with the external keyword? Or are you saying that the external keyword ie...

[pascal]procedure SomeProcedure; cdecl; external 'libSDL-1.2.0.dylib';[/pascal]

does not work on MacOS?

You probably know this already, but I will mention it just in case, If you plan to play with JEDI-SDL, don't forget to install SDL first. The relevant packages are...
http://www.libsdl.org/release/SDL-1.2.8.pkg.tar.gz for runtime
or
http://www.libsdl.org/release/SDL-de...2.8.pkg.tar.gz for the development package ( Project Builder + XCode )
It looks like the the other SDL libararies ( SDL_image, SDL_Mixer etc ) need to be built.