The CPAN shell (and module) automates or at least simplifies the building and installation of Perl modules and extensions. It includes some primitive searching capabilities and knows how to use Net::FTP, LWP, and certain external download clients to fetch distributions from the Internet. Then it automatically tests and installs them and their dependencies.
CPAN+changelog.pl is a wrapper script for the CPAN Perl module. It adds ChangeLog and BuildLog functionality. A ChangeLog allows an administrator to better decide if and when a module from CPAN should be upgraded. A BuildLog helps answer questions like, "When was module Foo installed?" or, "Were there any warnings when compiling Bar?"
The Finishing Scripts for Cluster Installations handle specific post-installation configuration that might not be convienent nor possible using existing cluster installation methods. The usual installation process is used to build a reasonably configured node, and the system then reboots into normal mode, achieves network visibility, and executes the finishing script. The finishing script handles all of the finer details of installing packaged or non-packaged software, tweaking installation, setting host/net specific parameters/files, etc. It is controlled via a single, easily modified script.