eXternalDB is an OTRS package, licensed under the Affero GPL v3 license terms, that allows to query external datasources.
OTRS is a powerful OpenSource ticketing system broadly used as a HelpDesk solution. eXternalDB works on top of it. Once installed you will be able to perform queries over any database with information related to your Help Desk operations. It is also coded using Perl and it uses the DBI interface for database connection. As a requisite, you will need the DBD drivers corresponding to your desired datasources installed in your system.
For those familiar with OTRS, eXternalDB is similar to SQL Box from the Administration menu but it has important differences:
The best way to catch a glimpse to this tool is to take a look to the Screenshots section. You will also be able to see a video explaining its installation and usage at the Installation section.