I've just written a Makefile for my own, that helps me to compile a .mxo object on Mac (using .o with possibly C++ class definitions),
without using Xcode. You can find the link on this page :
I was quite frustrated to find tutorials on Internet that do this kind of job but only with Xcode 3...And apparently this is a bit harder with Xcode 4. , because project templates need in that case to configure their templateInfo.plist in a precise manner (but maybe it's actually easy ????!! Or maybe I didn't find the good helps...)
The package has also inside the max SDK tools (with a 6.0.4 version). From the main directory, you can normally just drag into the src/ folder your .cpp files to compile and then type make (but see the README and the Makefile for particular notes). The package is already working with the example script found here http://code.google.com/p/maxcpp/
I don't know if it can help someone, and sorry I'm still quite a newbee in this kind of programming field, so I would be glad of course to have returns for people they accept to try it...I'm still learning how to write Makefiles that are more general and smarter conceived.