Butler.pm
   A Perl module that enables Perl scripts to access the Butler SQL database. Currently, this only works on Macs, so this will only be useful with MacPerl.
   http://remus.rutgers.edu/~petechen/Butler/Butlerpm.html

CPAN: Database Interfaces
   Listing of modules and their corresponding documentation.
   http://search.cpan.org/modlist/Database_Interfaces

Class::DBI
   Provides a convenient abstraction layer to a database.
   http://www.class-dbi.com/

DBD::MySQL
   Basic abstraction layer for working with databases in Perl, a driver for using MySQL with DBI and a pure-Perl implementation of the MySQL client-server protocol.
   http://dev.mysql.com/downloads/dbi.html

DBI.pm
   A Perl module used for the connection, retrieval and storage of data from various database applications.
   http://www1.uni-hamburg.de/RRZ/Software/DBI.pm/DBI.pm.html

DBIWrapper
   Designed to facilitate easier access to databases using DBI. High level methods for reading, writing, committing and rolling back transactions are provided.
   http://dbiwrapper.sourceforge.net/

DBIx::Browse
   Designed to facilitate the browsing (INSERT, UPDATE and DELETE) of related database tables. With demonstration.
   http://dbix-browse.sourceforge.net/

DBIx::Password
   Allows creation of a global password file for DB passwords.
   http://tangent.org/index.pl?node_id=420

MSSQL::DBlib & MSSQL::Sqllib
   Two Perl classes for accessing Microsoft SQL Server from Perl from MS Windows only.
   http://www.sommarskog.se/mssql/

Survey of DBI Wrappers
   Reviews and tabulates the features for many of the DBI wrapper modules available on CPAN.
   http://search.cpan.org/dist/DBIx-SQLEngine/SQLEngine/Docs/Related.pod

The Poop Scoop
   A review of the various modules available for Perl Object-Oriented Persistence (POOP), including RDBMS-OO mappers.
   http://poop.sourceforge.net/

libsite-db-perl
   Provides basic and easy database-connectivity through both URLs and standard DBD-parameters.
   http://freshmeat.net/projects/libsite-db-perl/?topic_id=68%2C90%2C45%2C910