Many tools available on a Debian system can be used for PackageManagement. Commonly used ones include:
apt - The main command-line package management tool
Synaptic - Graphical package manager
gnome-software - Software Center for GNOME
This page tries to list all software related to Debian package management.
Full list of package management tools
The apt package provides commandline tools for searching, managing, and querying information about packages, and access all features of the libapt-pkg library:
apt - high-level commandline interface for the package management system.
apt-cache - performs a variety of operations on APT's package cache.
apt-cdrom - used to add a new CD-ROM to APT's list of available sources.
apt-config - This program is used by the other apt utilities to provide a standard interface to the apt configuration settings.
apt-get - command-line tool for handling packages
apt-key - manage the list of keys used by apt to authenticate packages.
The dpkg package provides low-level infrastructure for handling the installation and removal of Debian software packages:
dpkg - a tool to install, build, remove and manage Debian packages.
dpkg-deb - Debian package archive (.deb) manipulation tool
dpkg-divert - override a package's version of a file
dpkg-maintscript-helper - works around known dpkg limitations in maintainer scripts
dpkg-query - show information about packages listed in the dpkg database.
dpkg-split - splits binary packages into smaller files and reassembles them(storage of large package files on small media)
dpkg-statoverride - override ownership and mode of files
dpkg-trigger - a tool to explicitly activate dpkg triggers
update-alternatives - maintain symbolic links determining default commands
apt-utils contains some less used commandline utilities related to package management with APT.
devscripts provides several scripts to make the life of a Debian Package maintainer easier
debuild - This tool is used for rebuilding packages
dpkg-dev provides the development tools (including dpkg-source) required to unpack, build and upload Debian source packages.
dpkg-scanpackages - create Debian Packages index files from binary packages (.deb and variants)
dpkg-scansources - create Debian Sources index files from source packages (.dsc)
apt-file - This tool searches for a filename installed by any package in the contents of sources.list.
apt-listchanges - This tool displays the relevant changelog entries whenever a package is upgraded.
apt-build - Used to build packages from the source files
apt-rdepends - This tool generates recursive dependency trees for a package.
apt-show-versions - shows all available versions of a package (allows wildcards), or all packages, and displays upgrade information where applicable.
dpkg-reconfigure - Allows a package to be reconfigured based on preferences (the same questions that are asked when the package is first installed).
apt-show-source - This is a variant of "apt-cache show" that shows information against the named source package, rather than the binary package.
apt-listbugs - This tool shows known critical bugs in named packages.
apt-sortpkgs - Sorts records and fields within the sources and packages files.
apt-extracttemplates - Extracts templates and install scripts from packages.
apt-setup - This tool configures the sources.list file.
apt-offline - Offline Package Management
deborphan - This tool scans the package database for unused or redundant packages
dpkg-www - Debian package management web interface - browse Debian packages on a local or remote host using a normal web browser.
?wajig - wrapper tool for apt-get, dpkg, apt-cache, wget, and others
Tools for managing a package repository
apt-cacher - This is an alternative tool to apt-proxy.
apt-ftparchive - generates, from a directory of packages, the Packages and Sources control files used for an apt repository.
apt-move - Moves a collection of Debian packages into a proper pool directory hierarchy as used by a package repository.
apt-transport-https - Allows apt to be configured to use https
dselect - Deprecated: superseded by aptitude
tasksel – Tool for selecting tasks for installation on Debian systems
PackageKit - Distro-agnostic frontend under developement
Get a list of package management tools (requires debtags): aptitude search '~Gadmin::package-management~Gsuite::debian'
TODO: add links to each command's manpage