Debconf

The Debian GNU/Linux distribution has a software configuration system built into it called debconf. Most Debian packages which make use of the debconf system will respond to the dpkg-reconfigure package_name

command. Running this command will typically start an interactive program (CLI or GUI, depending on how you have debconf set up) that walks you through configuring the package you specified.

The debconf package itself also uses debconf, so the frontend user interface can be (re)configured with: dpkg-reconfigure debconf