Unit Testing is a programming practice of testing code with code.  Programmers that use it start writing
better code, and reach a point where they wondered how they ever got by without it.  For an introduction
to unit testing, see Wiki:UnitTest, Wiki:ProgrammerTest, and Wiki:CodeUnitTestFirst at the
[wiki:Wiki:FrontPage C2.com wiki].

Here are some external sites with more information on unit testing:
 * [http://www.junit.org/ JUnit] The Java unit testing framework. Also contains a lot of very interesting articles relating to unit testing.
 * [http://www.mockobjects.com/ Mock Objects] Mock Objects are the key to real unit testing.
 * [http://www.xprogramming.com/ Ron Jeffries's web about Extreme Programming] Lists almost all unit testing frameworks for many languages.
 * [http://www.design-up.com/ Design Up] (French) A French website about extreme programming. Has excellent summaries about the XP method, OO design principles, and testing techniques.
 * [http://www.codeproject.com/gen/design/autp5.asp Unit Test Patterns] An article that presents common unit testing patterns.
