Apt

Apt (Advanced Package Tool) is a software package management system comprising a robust set of programs to manage the installation and removal of packages, with automated handling of dependencies. It originates from the Debian GNU/Linux distribution, but is available on other Linux distributions. Apt was written as a front-end to dpkg, which performs the the actual installation/removal of packages, but can also be used with rpm thanks to Conectiva's port.

Apt privides the underlying package manager - either dpkg or rpm - with the files it needs to satisfy dependencies. Using the package manager directly is sometimes frustrating, installing a package might require going to the internet and manually downloading several dependencies, which might then depend on other packages. Apt maintains a list of sources, from which it can get the necessary pacakge files with very little effort from the user. The sources might be on the local drive, CD or (most often) a remote repository.

Apt can update your whole system, even between major versions, in one command.

The Apt package itself includes the the following tools:
 * apt-get -- The command line tool to manage packages
 * apt-config -- Configure Apt (frontend for the /etc/apt/apt.conf file)
 * apt-cache -- get information from the cache, e.g. search package database
 * apt-cdrom -- Add a CD-ROM to the apt sources

Apt front-ends
(Yes, you can have a front-end to a front-end)
 * aptitude - text-based (ncurses)
 * synaptic - graphical (GTK)
 * dselect - text-based (ncurses) frontend to dpkg
 * gnome-apt - Gnome frontend to apt
 * feta - a front-end to apt, dpkg, debconf
 * wajig - a text-based/graphical(gjig) for many apt utilities.

Other apt related tools

 * apt-listbugs -- show bugs before installing a package
 * apt-listchanges -- List changelog before upgrading a package
 * apt-move -- move packages into a proper debian archive
 * apt-src -- manage source packages
 * equivs -- create dummy packages
 * apt-build -- build (and optimize) and install packages
 * apt-file -- search for files in packages (also packages that aren't installed)
 * apt-spy -- write a sources file based on bandwith tests
 * auto-apt -- on demand installing of packages
 * cron-apt -- Automatic upgrading
 * alien -- convert between different packaging formats
 * deborphan -- searches for orphaned packages