Working on huge web project of the drawer for single-line schemes and PLC-diagrams I implemented one small application upon it. DDM is used to draw any 2D grid-based maps with any background images, to put there units with variable properties, move/create/delete these units, so DDM is a good help to any D&D master, for example.
Soon, as I suppose, we will test it while playing regular D&D module. And now it's time to draw more another images for units and a couple of dungeon maps. Maybe later I'll try to create multi-player version with fog of war, action rights etc.
Created using svg+js on client-side and nodejs on server-side.
UPD. 3 oct 2011.
Has created a fully functional stand-alone single-user version, available at:
Free to use and modify (uses some GPL libs).