TestNG is a testing framework inspired from JUnit and NUnit but introducing some new functionalities that make it more powerful and easier to use, such as annotations, or the possibility to run your tests in arbitrarily big thread pools with various policies available (all methods in their own thread, one thread per test class, etc.). You can test that your code is multithread safe, there is flexible test configuration, support for data-driven testing (with @DataProvider), support for parameters, powerful execution model (no more TestSuite). There is a supported by a variety of tools and plug-ins (Eclipse, IDEA, Maven, etc.), it also embeds BeanShell for further flexibility, and there is default JDK functions for runtime and logging (no dependencies), and dependent methods for application server testing. TestNG is designed to cover all categories of tests, unit, functional, end-to-end, integration, etc.