DiaT is a Textadventure
CoffeeMudForAI is plaform to design AI in
Modular Minecraft server plugin - commands, events, ...
An 8 bit emulator created on the scratch, including an assembler.
A tool for roleplaying gamemasters
Unless you're getting started in Java, you probably don't want this.
Java Game, Simple 2d, for Practice and Examples
Spykee Control Interface in Java
3d peer to peer chatroom where associated pairs of text gravitate
A Java Tic Tac Toe Game
A cross-platform Java 2D graphics library using OpenGL.
Multi-user whiteboard emphasizing simplicity.