is a metapackage that depends on libc6-dev, gcc, g++, make, and dpkg-dev. One package that you might not be familiar with is dpkg-dev. It contains tools such as dpkg-buildpackage and dpkg-source that are used to create, unpack, and build source and binary packages.

contains many scripts that make the packager's maintenance work much easier. Some of the more commonly used are debdiff, dch, debuild, and debsign.

are scripts that automate common packaging tasks. dh-make can be used to do the initial "debianization" and provides many example files.

are used to create and apply patches, respectively. They are used extensively in packaging because it is easier, cleaner, and more efficient to represent small changes as patches rather than to have multiple copies of a file.

is a complete and free replacement for PGP used to digitally sign files (including packages).

simulates running a command with root privileges. This is useful for creating binary packages as a regular user.

dissect Debian packages and report bugs and Policy violations. They contain automated checks for many aspects of Debian Policy as well as for common errors.

constructs a chroot system and builds a package inside the chroot. It is an ideal system to use to check that a package has correct build dependencies and to build clean packages to be tested and distributed.