libmx is now at version 1.1, and contains updates to successfully compile on Mac OS 10.6 in 64 bit mode.
Notes: *1.1 update on 1/14/10* now works with SDL-1.12.14 and now is 64 bit on OS X works best with MacPorts, install autotools, libsdl, libpng, and libjpeg and configure with ./configure --prefix=/opt/local