A TestingFramework for VbClassic and ComponentObjectModel (COM):
http://comunit.sourceforge.net/
"COMUnit is a unit testing framework based on the architecture of JUnit, the current open source de facto standard for unit testing. COMUnit is a Visual Basic port of the JUnit framework that is designed to facilitate developing unit tests for Microsoft COM components and Visual Basic applications."
See: VbUnit, VbUnitThree, VbLiteUnit, SimplyVbUnit