Update: Some years have passed and now we're on Darwin 8 and FreeBSD 6+. So I took some time to refresh Darwin pkg tools and sync them with FreeBSD 6.2 allowing them to run on Mac OS X 10.4.8. This time pkg_* tools work with no feature cuts as the old release. Download here the source code. No binary distribution yet.
...outdated infos follow...
Update: More than a year has passed, we've seen lots of FreeBSD (almost 4.7) and a couple of major Darwin releases (6.1 now). I synced the Darwin pkg tools to FreeBSD 4.7-RC2 (should be okay for a while now), made some minor modifications (most notably using gnutar instead of tar into the tools) so they would compile and run almost smoothly... neat uh? :) At last Darwin pkg will run on Jaguar
So here we are: if you want to compile and install Darwin_pkg for yourself just download the source tarball and install the three components (this time we have libmd, libfetch and pkg_install tools). To do that just cd to each directory (./libfetch, ./libmd and ./usr.sbin/pkg_install) and type the usual "bsdmake" and then "bsdmake install". Thank you Apple and all the guys working on Darwin, nowadays things go so much smoothly.
If you want to quiclky install the binaries without going through the compilation step, just download the latest binaries, untar them and just type "./install.sh". You'll be silently done in a breeze.
... outdated infos follow...
After I fretted with darwin ports I decided I wanted to fix things to allow FreeBSD pkg_* work. Here you are with darwing pkg then. A quick patchup of src/usr.sbin/pkg_install from FreeBSD tree. I cut out md5 and libfetch, and didn't try to fixup with OpenSSL, I also tampered with arc4rand that now *does not* return a random number :).
Anyway if you want to give it a try, download darwin pkg, untar it, go to src/usr.sbin/pkg_install and type "bsdmake -DNO_OPENSSL=YES" and then "bsdmake install", and you're done with it.
You can also download binaries for darwin/powerpc 1.3. The install script will silently install pkg_* and pkg_*.1.gz in /usr/sbin and /usr/share/man/man1.
As I compile ports I'll also build packages that you can download on Darwin packages. Assume you have package.tar.gz, you can add it with pkg_add package.tgz. You can list packages installed on your system with pkg_info and eventually remove with pkg_delete packagename. Hope you enjoy.
See also darwin ports, a patchkit to allow The FreeBSD Ports Collection run on Darwin.