...Tiled is a general purpose tile map editor for all tile-based games, such as RPGs, platformers or Breakout clones. Tiled was originally written in Java. In 2008, work began to develop a faster, better looking, and easier-to-use version of Tiled based on the Qt framework. This decision was made as the Qt framework has a greater feature set than is offered by the standard Java libraries.
Ethanon is a 2D game engine focused on the recent video cards for hardware acceleration and shader effects. The engine provides high-quality light an shadow effects with an easy visual interface and a simple and direct scripting system.
OpenGDK is short for Open Game Development Kit. It's supposed to be a plug-in BASED (it's different from OGRE. OGRE is plug-in friendly), cross-platform, open source, general purpose (2D, 3D, client, server, editor), game development kit.
Interactive aims to be a cutting edge Opensource, community driven MMO Engine for the indie community. Our goal is to provide a service like AAA companies have in Hero Engine and Big World.
A multiplayer only FPS involving veichle driving in a futuristic populated living city with a intuitive and user friendly map editor. Written in C++ (but some content creation tools are in Java) and aims to be portable.
SGE (Serpent Game Engine - by Erico GR) is a simple but POWERFUL Java tool for creating 2D games in no time. You can use a rich Level Editor to build xml levels with many layers, objects and actors.
A clone of the old DOS game Commander Keen. It's written in C++ and uses the SDL library so it's mostly platform independent. A map-editor (Java 1.5) is also included.
Pangaea will be a robust and feature filled game engine built using Allegro (http://alleg.sourceforge.net) It will be similar to Final Fantasy 1-3, etc., complete with map editor/world builder.
Orange 3D, a game engine distributed under the zlib/libpng license, is an all in one solution, with IDE, level editor, 2d painter, 3d modeler, and possibly audio editing software all in one clean package, for free!
Originally a fork of Legend of Mazzeroth, this project aims to create an engine rather than a game. It aims to be a 2D MMORPG engine, fit for easy customization through Ruby. It also features an edit of Tiled, the map editor made at www.mapeditor.org