Run Photo Marathons
Find as much words you can in a schema (game console based).
A Java chess engine using xboard protocol
A math flashcard-like game
A Simple and Easy to Use User Interface for Private Bukkit Servers
An e-stim signal generator in java
An Open Engine for use on the OUYA
Little game background framework in java.
An extensible development framework for roleplay games.
(currently talkie-talkie, will be playable soon!)
CoffeeMudForAI is plaform to design AI in
A java-based, purely object-oriented chess engine.
Modular Minecraft server plugin - commands, events, ...
Unless you're getting started in Java, you probably don't want this.