Concept

You get a regular Debian system

A/DeMuDi is not a separate distribution to Debian, it's just a custom way to install an ordinary Debian system, which gets automatically configured for audio work.

The APT repository

A/DeMuDi has its own APT repository, where all packages part of the distribution reside, and which is used to build the installable ISO image. Such repository is basically a merge of subset of a some external repositories plus a few custom packages.

Almost all packages of the A/DeMuDi repository are taken from Debian etch, with the exception of a few packages which are taken from a custom repository and that have still to be uploaded to Debian.

Here is a listing of the various components of the A/DeMuDi repository, along with their original APT source line:

etch	deb http://ftp.debian.org/debian etch main
sid	deb http://ftp.debian.org/debian sid main
custom	deb http://archive.64studio.com/ custom main

A detailed list of which packages are taken from which repository is available here.

You can install packages from Debian

Nevertheless, as A/DeMuDi is a regular Debian system, you can also access to the whole pool of official Debian packages, even those not contained in the A/DeMuDi CD-ROM. See InstallApt to check how to do that.