Apt-Pinning
John H. Robinson, IV: I will show you a way that you can have apt mix-and-match between Stable, Testing, and Unstable sources. This will allow you to run a mostly-Stable system, but also track the latest and greatest of those packages that you are most keenly interested in.
It is much easier to install XML::Atom on a Debian system if you have first issued the following command:
apt-get -t testing install libxml-libxml-perl libdatetime-perl libdigest-sha1-perl libwww-perl libxml-libxslt-perl