yum - A wrapper for rpm that automatically retrieves packages from remote package feeds. Downloads, documentation, a TODO, and a list of repositories provided. - http://www.linux.duke.edu/projects/yum/
apt4rpm - A tool to convert a repository of RPMs into an APT feed for remote system upgrades. Downloads, documentation, and a list of repositories provided. - http://apt4rpm.sourceforge.net/
AutoRPM - Synchronizes a local database or directory with remote packages. Other small utilities are provided as well. - http://www.kaybee.org/~kirk/html/linux.html
AutoUpdate - A Perl script which automatically downloads and upgrades packages residing on multiple FTP sites. Documentation and download links are provided. - http://www.mat.univie.ac.at/~gerald/ftp/autoupdate/index.html
OpenPKG - A cross-platform RPM-based package management system. - http://www.openpkg.org/
gbuild - A script written to simplify the building of packages from CVS. Screenshots, download links, and documentation provided. - http://cryon.com/gbuild/
Purp - An ncurses front-end to the rpm tool. Downloads, documentation, screenshots, and status provided. - http://www.lysator.liu.se/purp/
rpm2html - Generates HTML pages containing information on RPM packages, including general package information, dependencies and files. Downloads, documentation, FAQ, and mirrors provided. - http://rpmfind.net/linux/rpm2html/
Rpm Browser For Windows - A Windows tool to examine the structure and contents of RPM packages. - http://www.laysi.com/rpmbw/
Glitter - A console front-end to the rpm tool. Download links, documentation, screenshots, and a TODO provided. - http://www.xs4all.nl/~bvermeul/glitter/
pkgbuild - A graphical development environment for building RPM packages. Downloads, documentation and screenshots provided. - http://rpm-pkgbuild.sourceforge.net/