i made a box2d playground a while back but eventually got bored and it sat on my hard drive for a year or something.
the export function will write a .lua in "AppData\Roaming\LOVE\box2d_editor"
buttons are not labeled (too lazy) so this is what they do:
-T: enable/disable test mode
-del: delete shape selected
-left mouse button: drag shapes around in test mode
-middle mouse button: move camera
-right mouse button: place last vertex in polygons and chainshapes
thats very nice, its just lovely to see physics at work
i just gotten to box2d for love2d, ive used ofxbox2d with openframeworks for a while so it should be easy to convert the ideas over