Sliceconf is a project mainly written in Ruby, it's free.
Sprinkle a debian slice with REE, nginx, unicorn and mongo. Configure as monitored app or db server.
Prepare & Deploy a debian lenny slice with essential components including Ruby Enterprise Edition, Rails, nginx, unicorn and mysql/mongo db drivers.
The created slice should allow ssh key-based authentication to a sudo-user.
Work In Progress on db drivers and per-app configuration.