JUnit 3 allows to run test cases by means of Java applications called test runners. JUnit 3.8.2 provides three different test runners out of the box: two graphical (Swing and AWT based) and one textual that can be used from the command line. The JUnit framework provides separate class loaders for each test, in order to avoid side effects among tests.
It is a common practice that build tools (such as Ant or Maven) and Integrated Development Environments -IDE- (such as Eclipse and IntelliJ) implement its own JUnit test runner.
The following image shows what the previous test looks like when we use the JUnit Swing runner, and also when we use Eclipse to run the same test case.