PNUnit stands for "Parallel NUnit." It is an extension of NUNit developed by Pablo Santos Luaces and his team at Codice Software for their internal use in testing the Plastic (TM) Software Configuration Management System. Codice released PNUnit to the community in 2007.
As part of the NUnit 2.5 release, we worked with the NUnit and PNUnit teams worked together to make PNUnit work with NUnit without any modifications. PNUnit is now included in the NUnit distribution.
PNUnit is not intended for "casual" parallelism merely to make the tests run faster. Rather, it's intended as a way to test applications composed of distributed, communicating components. Tests of each component run in parallel and use memory barriers to synchronize their operation.
PNUnit uses a special executable to launch its tests. The launcher reads an xml file that specifies the tests to be executed and where they should run, whether on the same machine or on another machine on the network.
PNUnit will be integrated with NUnit so that parallel, distributed tests may be used through the normal NUnit console or gui runners.