Please don't use the old *.zip archives anymore. They are not being maintained anymore. You can download *.ppmx files directly from the PPM build status pages and install them with:

    ppm install FooBar-1.23.ppmx

A .ppmx file is just the usual tarball of the blib tree plus an additional *.ppd included. These files are the same tarballs that PPM itself would download from the repo.