FABLE or Fire Ant Box2d Level editor is a FREE Box2d Editor. Containing tools to aid developers to generate astouning box2d scenarios with a graphic user interface in a painless manner.
A great feature of the editor is the one click running simulation. This feature allows you to see and interact with the running instance of your world to see if it meets what you have in your mind. So if for example you are creating a tank you can see how does it responds and tweak diferent parameters, positions and fixtures to make it perform flawlessly all from a gui and with easy to use tools.
This editor fully supports box2d, that is all the joints, bodies and fixtures. Including gearJoint and pulleyJoint :).
This software can also handle textures, so you can import images to the software and attach them to the bodies, this also in a painless manner. A very usefull tool for textures is the autosplitter. This tool splits the elements in a texture, so for example if you add an image that contains several elements this tool can extract them and let you handle them individually.
Also when you are about to publish the project the tool takes care of scaling, cropping and sorting the textures in the texturesheet so to optimize and reduce the size.
This tool can export the world to xml, an xml that contains the info of the world as well as the info of the texture mapping or can export code for ios using cocos2d instructions.
The tool allows you to save your work in the .ble format. This includes images and definitions.
Here are some videos to show the software.