Our mirror is updated nightly and FAI is set up to use the mirror when updating packages. Since we have two separate types of robots, we use FAI's classes and hooks facilities to create two separate installations. This allows fine grained control over installation of things such as: the kernel image, the X configuration files, the hard drive partitioning scheme, the packages to install, the network configuration and the serial port configuration. Since packages often change, the systems are kept up-to-date using the usual Debian facilities (apt and its front ends). In addition, locally developed software is managed using CVS.