PyUnitOSX is a build of the PyUnit Python testing framework — a Python language version of JUnit. JUnit was written by Kent Beck and Erich Gamma, and is, in turn, a Java version of Kent Beck's Smalltalk testing framework. Each is the de facto standard unit testing framework for its respective language, and therefore both are a strong basis for an effective and elegant Python framework.

This version of PyUnit requires the Python tkinter module for its interface. Tkinter can be installed with the Python PackageManager application, available from the MacPython site. The package also requires the Aqua version of Tcl/Tk.