The PeopleTools blogging team just released an unsupported tool for test driven PeopleCode development: PSUnit. The blog post contains the PSUnit source code and a document that describes how to use PSUnit to test drive PeopleCode development. If you are familiar with one of the xUnit frameworks (jUnit, nUnit, utPLSQL, Test::Unit, etc) and eXtreme Programming, then you know the value of test driven development. If you are new to Test Driven Development (TDD), then take a look at Kent Beck's book Test Driven Development by Example.
As a fellow PeopleCode programmer, I believe we can create better solutions by applying proven disciplines and methodologies to PeopleCode development.