Instructions (and comments):

I will describe how I compiled them, you are free to change it according to your needs. I compiled them with maximum compatibility for Mac OS X 10.3.9 and higher system with no extra libraries installed.

* cdrtools:
I aplied a patch to the source, making mkisofs able to create DVD-Audio iso files. (patch in root folder: 'mkisofs-2.01.01-dvd-audio.diff'). PowerPC and Intel version build on Mac OS X 10.5.6.

Commands:
bash#: make

* dvda-author:
Build on Mac OS X 10.3.9 for the PowerPC version and on Mac OS X 10.4.11 for the Intel version.

Commands:
bash#: ./configure --enable-flac-build --without-ogg --without-sox
bash#: make

* dvdauthor:
Build on Mac OS X 10.3.9 for the PowerPC version and on Mac OS X 10.4.11 for the Intel version.

Commands:
bash#: ./configure
bash#: make

Note: libiconv.a is staticly linked in, since it's missing in Mac OS X 10.3.9 by default.

* ffmpeg(-mt):
PowerPC (including G3 version) version build on Mac OS X 10.5.6. Intel version build on Mac OS X 10.4.11. Used ffmpeg-mt (multi processor / core version) for PowerPC (with altivec) and Intel version. Used ffmpeg for G3 version, changed some included header files so it compiles using the 10.3.9 SDK (in cmdutils.c and libswscale/utils.c).

ffmpeg-mt version: git-2bbb64d, libswscale version: git-svn-r32676
ffmpeg version: SVN-r26116

For the ffmpeg-mt version you'll need yasm on an Intel Mac and gas-preprocessor.pl on a PowerPC Mac.

Commands:
yasm (only Intel):
bash#: ./configure
bash#: make
bash#: sudo make install
gas-preprocessor.pl (only PowerPC G4, G5):
bash#: sudo chmod 755 gas-preprocessor.pl
bash#: sudo cp gas-preprocessor.pl /usr/local/bin/ (or other binary path in PATH)

G3:
bash#: ./configure --disable-muxers --disable-encoders --enable-muxer=avi --enable-muxer=mpeg1vcd --enable-muxer=mpeg2dvd --enable-muxer=mpeg2svcd --enable-muxer=wav --enable-muxer=mp3 --enable-muxer=flac --enable-encoder=ac3 --enable-encoder=mp2 --enable-encoder=libmp3lame --enable-encoder=flac --enable-encoder=wav --disable-protocols --enable-protocol=file --enable-protocol=pipe --disable-bsfs --enable-libmp3lame --disable-shared --enable-gpl --enable-encoder=mpeg4 --enable-encoder=mpeg1video --enable-encoder=mpeg2video --enable-muxer=image2 --enable-encoder=mjpeg --disable-bzlib --disable-network --enable-encoder=pcm_s16le --enable-pthreads --disable-filters --enable-filter=pad --enable-filter=scale --enable-filter=crop --enable-cross-compile --arch=ppc --extra-cflags='-arch ppc -isysroot /Developer/SDKs/MacOSX10.3.9.sdk -mmacosx-version-min=10.3.9' --extra-ldflags='-arch ppc -isysroot /Developer/SDKs/MacOSX10.3.9.sdk -mmacosx-version-min=10.3.9' --enable-muxer=pcm_s16le --target-os=darwin --disable-altivec
bash#: make

PowerPC (G4, G5):
bash#: ./configure --disable-muxers --disable-encoders --enable-muxer=avi --enable-muxer=mpeg1vcd --enable-muxer=mpeg2dvd --enable-muxer=mpeg2svcd --enable-muxer=wav --enable-muxer=mp3 --enable-muxer=flac --enable-encoder=ac3 --enable-encoder=mp2 --enable-encoder=libmp3lame --enable-encoder=flac --enable-encoder=wav --disable-protocols --enable-protocol=file --enable-protocol=pipe --disable-bsfs --enable-libmp3lame --disable-shared --enable-gpl --enable-encoder=mpeg4 --enable-encoder=mpeg1video --enable-encoder=mpeg2video --enable-muxer=image2 --enable-encoder=mjpeg --disable-bzlib --disable-network --enable-encoder=pcm_s16le --enable-pthreads --disable-filters --enable-filter=pad --enable-filter=scale --enable-filter=crop --enable-cross-compile --arch=ppc --extra-cflags='-arch ppc -isysroot /Developer/SDKs/MacOSX10.3.9.sdk -mmacosx-version-min=10.3.9' --extra-ldflags='-arch ppc -isysroot /Developer/SDKs/MacOSX10.3.9.sdk -mmacosx-version-min=10.3.9' --enable-muxer=pcm_s16le --target-os=darwin

bash#: make

Intel:
bash#: ./configure --disable-muxers --disable-encoders --enable-muxer=avi --enable-muxer=mpeg1vcd --enable-muxer=mpeg2dvd --enable-muxer=mpeg2svcd --enable-muxer=wav --enable-muxer=mp3 --enable-muxer=flac --enable-encoder=ac3 --enable-encoder=mp2 --enable-encoder=libmp3lame --enable-encoder=flac --enable-encoder=wav --disable-protocols --enable-protocol=file --enable-protocol=pipe --disable-bsfs --enable-libmp3lame --disable-shared --enable-gpl --enable-encoder=mpeg4 --enable-encoder=mpeg1video --enable-encoder=mpeg2video --enable-muxer=image2 --enable-encoder=mjpeg --disable-bzlib --disable-network --enable-encoder=pcm_s16le --enable-pthreads --disable-filters --enable-filter=pad --enable-filter=scale --enable-filter=crop --enable-muxer=pcm_s16le --target-os=darwin
bash#: make

* lame:
Lame is compiled staticly and linked into ffmpeg(-mt). Build on Mac OS X 10.5.6 on PowerPC and on Mac OS X 10.4.11 on Intel. 

Commands:
Intel:
bash#: ./configure --disable-shared --disable-frontend
bash#: make
PowerPC:
bash#: HOST_CC=gcc CC="gcc-4.0 -arch ppc -isysroot /Developer/SDKs/MacOSX10.3.9.sdk -mmacosx-version-min=10.3.9" CXX="g++-4.0 -arch ppc -isysroot /Developer/SDKs/MacOSX10.3.9.sdk -mmacosx-version-min=10.3.9" ./configure --disable-shared --disable-frontend
bash#: HOST_CC=gcc CC="gcc-4.0 -arch ppc -isysroot /Developer/SDKs/MacOSX10.3.9.sdk -mmacosx-version-min=10.3.9" CXX="g++-4.0 -arch ppc -isysroot /Developer/SDKs/MacOSX10.3.9.sdk -mmacosx-version-min=10.3.9" make

* vcdimager:
Build on Mac OS X 10.3.9 for the PowerPC version and on Mac OS X 10.4.11 for the Intel version. Since Burn 2.0u we're using the command line frontend (was the xml frontend).

Commands:
bash#: ./configure --disable-shared --without-xml-frontend
bash#: make

* movstuff:
Build with Xcode on Mac OS X 10.5.6 on both PowerPC and Intel. Projects used in Burn: movtowav and movtoy4m.