It's hard to come up with good teaching examples of TestDrivenDevelopment that are large enough to be meaningful but small enough to be understood quickly.  There are some old chestnuts:  Kent Beck used the Money example in ''Test Driven Development: By Example'' (ISBN:0321146530).  Uncle Bob Martin and Ron Jeffries have frequently used the Bowling Game example.

== Step by step examples ==
 * A StoryTestDrivenDevelopmentExampleInCsharp
 * Ron Jeffries' [[http://www.xprogramming.com/xpmag/acsBowling.htm|Adventures in C#: The Bowling Game]] explores bowling scoring in C#.
 * William Wake's [[http://www.xp123.com/xplor/xp0201/index.shtml|Test-First Challenge]] builds a spreadsheet program in Java.  This is one of the best on-line demos I know, as it lets ''you'' write the code to make his tests pass.  Translating the tests to other languages should be simple.  There are also links to several solutions.
 * William Wake's [[http://www.xp123.com/xplor/xp0101/index.shtml|The Test-First Stoplight]] includes a simple Java example of a Person class.
 * Will Stott and James Newkirk's [[http://msdn.microsoft.com/msdnmag/issues/04/04/ExtremeProgramming/|Test-Driven C#: Improve the Design and Flexibility of Your Project with Extreme Programming Techniques]] includes some simple examples
 * Christopher Bennage's [[http://devlicio.us/blogs/christopher_bennage/archive/2007/08/26/tdd-example-querying-a-repository.aspx|TDD Example: Querying a Repository]] shows a simple test using a database and C#.
 * Brian Marick's [[http://www.exampler.com/blog/2007/06/26/a-workbook-for-practicing-test-driven-design-draft/|A workbook for practicing test-driven design (draft)]] uses Java to develop an interface for a simple hierarchical data format.
 * Scott Bellware's [[http://codebetter.com/blogs/scott.bellware/archive/2005/11/23/135001.aspx|Test-Driven Development Example: Factorial]] walks through developing a factorial calculator in C#.
 * Olof Bjarnason has collected his own list of [[http://sites.google.com/site/tddproblems/|TDD Problems]]

== Code that's been developed using TDD ==
 * Brian Button's [[http://www.agileprogrammer.com/oneagilecoder/archive/2004/08/10/2868.aspx|example of TDDed code]]

== Problem suggestions that might make good examples ==
 * A mailing list that supports entering a future address change for a person
 * Alistair Cockburn's [[http://alistair.cockburn.us/index.php/Coffee_machine_design_problem,_part_1|Coffee Machine]] might make a good example problem.  (also see [[http://alistair.cockburn.us/index.php/Coffee_machine_design_problem%2C_part_2|part 2]].)

== Descriptions and explanations of TDD ==
 * Scott Ambler's [[http://www.agiledata.org/essays/tdd.html|Introduction to Test Driven Design]] has a good description before it dives into Test Driven Database Development.
 * Nancy Corbett's [[http://www.developer.com/design/article.php/3622546|Test Driven Development, a Portable Methodology]] at Developer.com