Yes clearly it's been done way too many times, Tic tac toe. Even worse is I haven't implemented any game AI here, in this game two (human) players play against each other.

Whats interesting about this:

• I wrote a little separated engine to process the game in pure javascript.
• I wrote a unit-test suite with QUNit
• I hooked up the engine with the UI with JQuery (this is more obvious then interesting)

See the screenie below, keeps track of player names, game count and score:

• Check it out live here
• See the QUnit Test Suite

I will (if there is any interest) put this out on github. Please do tell me if you find any mistakes in the design, structure or tests here.