Nagle's approach moves test automation to the third level as it uses a nontechnical front end (a table-driven approach that is implemented in MS Excel format) that describes the tests to be performed, lays out the test scenarios, and implements the steps to be executed. When the tables are parsed by the DDE, the DDE executes automated tests without the user needing to write test script code.
Carl Nagle of SAS Institute developed this framework for SAS (SAS Institute owns the intellectual property rights to the DDE), but also released it to the public domain as is indicated in the following copyright information:
Copyright (2001) SAS Institute Inc. All rights reserved.
NOTICE: Permission to use, copy, modify ...