Calamares is an installer framework. By design it is very customizable,
in order to satisfy a wide variety of needs and use cases.

Calamares aims to be easy, usable, beautiful, pragmatic, inclusive and
distribution-agnostic.

Got a Linux distribution but no system installer? Grab Calamares, mix
and match any number of Calamares modules (or write your own in Python
or C++), throw together some branding, package it up and you are ready
to ship!

(The above applies to FreeBSD as well)

WWW: https://calamares.io/