This repository serves as an archive for Apple's Core Audio Utility Classes, as available from Apple.
The reason for the archive is that Apple usually drops support for older OSes. For example, the 1.03 version of the files are not supported for OX 10.6 or earlier, whereas the previous versions are (or might be; I'm not actually sure).
The ZIP files are verbatim downloads from Apple's web site. The PATCH files are required for clean compilations; you may safely ignore "applied with fuzz" warnings from the patch utility. Also, don't forget to use the -p0 option to patch or you'll wonder why patch can't find the files it's looking for...