CoffeeMud is a text-based virtual reality game engine (a MUD). It is a mature, full-featured Java codebase. It includes web (HTTP) and email (SMTP) servers, chat (IMC2 and I3) and web clients, and supports ANSI, MXP, and MSP.
Jepe is an Pokémon Game engine. We have been working on pokémon fan games for quite a while now, but found no easy framework to program them. Therefore we are making this engine.
Friendly Object-Oriented Game Library , 2D Java Game Engine based on Slick2D and LWJGL.
This library was designed for students and primer Java programmer.