Agnostic automated deployment
I use Puppet for some of the deployements / initial configuration of server. Maven and Ant for Java based projects.
What do you use to automatically deploy applications for various kinds of server applications (web, socket, daemon) that uses various technologies (different DBs, languages, etc)? 
Here we use Python, Java and Ruby, and may use other languages as well in the future.
Update: I ended up using Puppet to manage all server setup, configs AND deploy. To trigger the deploy of newer versions I ended up using Python Fabric scripts.