CPAN-Changes-Diff is a project mainly written in Perl, it's free.
Diff changes between two CPAN releases
Find the changes file within a CPAN distribution and return the difference bwtween two changes file.
Changes will be looked for in one of several filenames, Changes, ChangeLog with no file extension or .txt or .pod
If the changes file is written in pod the result will be the difference after formatting into plain text
This software is copyright (c) 2011 by Graham Barr [email protected]
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.