Agnostic automated deployment
For Python you could use Fabric or Paver
For Ruby, there's capistrano and 'vlad the deployer'
For Java, it's the Ant.
For PHP/Python projects I also use Peritor Webistrano, a neat frontend for capistrano. It involves changing a few of the default recipes to remove the rails-specific stuff, but it's worth it once you get it setup correctly.
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.