NUnit is an evolving, open source framework designed for writing and running tests in Microsoft .NET programming languages. NUnit, like JUnit, is an aspect of test-driven development (TDD), which is part of a larger software design paradigm known as Extreme Programming (XP). The NUnit development team includes Jamie Cansdale, Gary Feldman, Charlie Poole and Michael C. Two.
NUnit has a graphical user interface (GUI) similar to that used in JUnit. Tests can be run continuously. Results are provided immediately. Multiple tests can be run concurrently. No subjective human judgments or interpretations of test results are required. The simplicity of the framework makes it possible to easily correct bugs as they are found. The current version of NUnit is written in C#, an object-oriented programming (OOP) language that combines the power of C++ with the simplicity of Visual Basic. NUnit is one of a family of related testing frameworks known as xUnit.