A Tour of the Repository
Most files on CPAN come from PAUSE, which provides the authors and modules directories. There’s more to CPAN than just the modules. Here’s a short tour of the more interesting parts.
This directory, mirrored from PAUSE, contains numerous subdirectories, arranged by the author ID of the contributor under the id subdirectory. The first level of directories is the first letter in the author ID, the second level is the first two letters, and the final level is the full author ID. For instance, for the author NANIS (Sinan Ünür), the path under authors is id/N/NA/NANIS. Under that directory is everything Sinan has uploaded—but not removed; see BackPAN.
Some authors have a directory with their full name, such as Hugo_van_der_Sanden. The authors directory had a flatter structure when there weren’t that many authors. As CPAN became more popular—there are now over 9,000 registered authors—PAUSE partitioned the author names into the three-level structure.
This directory is used to hold the Perl documentation, as well as various commentary on it, but it is no longer maintained. There’s still some interesting material in there, but it’s no longer the main source of Perl information. For online documentation, use http://perldoc.perl.org for the core Perl information or one of the Perl module sites for module documentation.
Curiously, this directory is not where you find the module, but all of the special index files that the CPAN clients use to turn a package ...