debconf is a software utility for performing system-wide configuration tasks on Unix-like operating systems.

The design of debconf allows for front-ends for answering configuration questions to be added in a modular way, and there exist several, such as one for dialog, one for readline, one that uses a text editor, one for KDE, one for GNOME,[3] a Python front-end API, etc.

The new implementation is currently only used in the installer, but is intended to eventually replace the original entirely.

Debconf does not physically configure any packages, but asks the user certain configuration questions stored in the .templates file, under the direction of the package's maintainer scripts (.config, .postinst, etc.).

Typically, the .config script uses debconf to ask questions, while .postinst applies configuration changes to the unpacked package in reaction to the answers; however, this can vary due to technical requirements.