A downloadable zip file

Generic game classes

AsynchronousPlayer.java
Board.java
BoardStats.java
DefaultGameEventListener.java
DefaultPlayer.java
GameEventListener.java
GameMaster.java
MinimaxPlayer.java
Move.java
Player.java

Four in a row classes

C4Applet.java
C4Board.java
C4Move.java
C4Row.java
C4Slot.java
C4SlotListener.java
C4Stats.java