I'm still doing research on Debbie and Kraken. I found that the only way to use the backup facilities of either was to use an agent included with each of the respective backup aps that is installed on the target desktops.
Read the blog entry here
Windows Home Server (Kraken) uses a install module that can be installed ONLY on Windows boxes. Bacula on Debian has a similar method but has agents that can be installed on practically everything. Advantage — Bacula.