The current release is passwdd-0.08.tar.gz. Note that this is a gzipped tar file. You will need the GNU gunzip program, part of the gzip package, to extract the files in the archive. You can get the latest version of any of the GNU tools from ftp://ftp.gnu.org/pub/gnu/.
There are also previous releases available through ftp://ftp.varna.net/pub/linux/passwdd/ along with contributed binary releases available through ftp://ftp.varna.net/pub/linux/passwdd/binaries/
The primary alternate directory for passwdd is ftp://metalab.unc.edu/pub/linux/system/security/.
The offical web place for documentation of passwdd is available at http://www.varna.net/~alex/passwdd.