Packages 
Package Description
junit.extensions
Provides extended functionality for JUnit v3.x.
junit.framework
Provides JUnit v3.x core classes.
junit.runner
Provides JUnit v3.x test runners.
junit.textui
Provides JUnit v3.x command line based tool to run tests.
org.junit
Provides JUnit core classes and annotations.
org.junit.experimental  
org.junit.experimental.categories  
org.junit.experimental.max  
org.junit.experimental.results  
org.junit.experimental.runners  
org.junit.experimental.theories  
org.junit.experimental.theories.suppliers  
org.junit.function  
org.junit.matchers
Provides useful additional Matchers for use with the Assert.assertThat(Object, org.hamcrest.Matcher) statement
org.junit.rules  
org.junit.runner
Provides classes used to describe, collect, run and analyze multiple tests.
org.junit.runner.manipulation
Provides classes to filter or sort tests.
org.junit.runner.notification
Provides information about a test run.
org.junit.runners
Provides standard Runner implementations.
org.junit.runners.model  
org.junit.runners.parameterized  
org.junit.validator