This is the Debian package repository for the Aegir project.
In your /etc/apt/source.list:
deb http://debian.aegirproject.org/ stable main deb-src http://debian.aegirproject.org/ stable mainYou may want to change "stable" for another release if you want to try development code. For more information on this archive and the way it is managed, see the http://community.aegirproject.org/debian.
This archive self-signs packages uploaded to it (and packages uploaded are verified against a whitelist of trusted uploaders) using OpenPGP (GnuPG, to be more precise).
The key of the archive is in the key.asc file. You should add the key using something like this:
wget http://debian.aegirproject.org/key.asc apt-key add key.asc apt-get update