My goal is to install the GD Graphics library, and to get png support I must install libpng. I thought Mac OS X already had libpng installed, but gd doesn't seem to agree, so I'm trying to install libpng from the source code. Libpng requires zlib, so I've downloaded, (./configure, make, make install) zlib-1.2.3. Seemed to work. Then I downloaded the source for libpng.1.2.12 and I'm trying to install it. The libpng install procedure doesn't follow "normal unix standard". I have to find my own makefile and put the already built zlib in a neighbour directory because it won't detect that zlib is installed in /usr/local/lib and /usr/local/include. Using the makefile.darwin to run "make test" I get the following error: Code: cc -dynamiclib \ -install_name /usr/local/lib/libpng12.0.dylib \ -current_version 0.1.2.12 -compatibility_version 0.1.2.12 \ -o libpng220.127.116.11.12.dylib \ png.pic.o pngset.pic.o pngget.pic.o pngrutil.pic.o pngtrans.pic.o pngwutil.pic.o pngread.pic.o pngrio.pic.o pngwio.pic.o pngwrite.pic.o pngrtran.pic.o pngwtran.pic.o pngmem.pic.o pngerror.pic.o pngpread.pic.o -L../zlib -lz ld: Undefined symbols: _png_mmx_support _png_combine_row _png_do_read_interlace _png_read_filter_row /usr/bin/libtool: internal link edit command failed make: *** [libpng18.104.22.168.12.dylib] Error 1 Any thoughts? I've also tried the generic makefile.gcc without success. Strangely, /usr/local/include now holds four png related files (libpng libpng12 png.h pngconf.h); I don't know if they've always been there. I did a make install just for the heck of it, but it reported the same error.