This document discusses unit testing and regression testing for PL/SQL. It introduces three developers - Jacek Gabal, Pavel Kaplya, and Stefan Poschenrieder - who advocate for and actively practice unit testing. They discuss why unit and regression testing are important, tools for testing PL/SQL like utPLSQL, and how Stefan has used Excel as a testing harness for utPLSQL. The document also summarizes new features of utPLSQL version 3.