JUnit is a regression testing framework written by Erich Gamma and Kent Beck. It is used by the developer who implements unit tests in Java.

Cactus is a simple test framework for unit testing server-side java code (Servlets, EJBs, Tag Libs, Filters, ...). The intent of Cactus is to lower the cost of writing tests for server-side code. It uses JUnit and extends it.

Lightweight framework allowing to run EJBs without the application server support for testing purposes.

StrutsTestCase is an extension of the JUnit TestCase class that allows testing of individual Action objects with or without a running servlet engine. This framework provides both mock servlet objects as well as Cactus support to simulate the environment.

SQLUnit is a regression and unit testing harness for testing database stored procedures. An SQLUnit test suite would be written as an XML file. The SQLUnit harness, which is written in Java, uses the JUnit unit testing framework to convert the XML test specifications to JDBC calls and compare the results generated from the calls with the specified results.

UISpec4J is an Open Source functional and/or unit testing framework for Swing-based Java applications, built on top of the JUnit test harness. What makes it special is that its APIs are designed to ease the testing process by making the test scripts as close possible to human-readable text.

DbUnit is a JUnit extension (also usable with Ant) targeted for database-driven projects that, among other things, puts your database into a known state between test runs. This is an excellent way to avoid the myriad of problems that can occur when one test case corrupts the database and causes subsequent tests to fail or exacerbate the damage.

JTestCase uses XML file to organize multi-testcase data and asserting conditions (action and expected result), and provides a set of easy-to-use methods to retrieve test cases out from XML, and asserts results against those expected ones in data file.

JUnitPerf is a collection of JUnit test decorators used to measure the performance and scalability of functionality contained within existing JUnit tests.