xUnit is the collection name for unit-testing compliant frameworks following a specific architecture. Implementation differs from language to language but the framework should consist of a Test Runner, Test Case, Test Fixture (Context), Test Suite, Test Execution, Test Result Formatter and Assertions
xUnit has been implemented for most languages, examples include JUnit, NUnit, CUnit, CppUnit, xUnit.net and more. The first implementation was made for Smalltalk by Kent Beck and is called SUnit.