CFEngine is a way of managing a large number of machines and keeping them in sync. It was written by Oslo university to manage all their machines. It even (apparently) supports MicrosoftWindows. CFEngine tends to have a bit of a bias towards systems like this (lots of identical machines in a university enviroment) however it can be used when the machines are more different.

CFEngine works by pulling configs from a central site, and running it on each machine. It can also push configs out etc.

See CFEngineNotes for some of the tricks and traps we found along the way