3D10.net is an online tabletop simulator that runs in your broswer in 3 glorious dimensions. Build units and unit sets to meet the needs of any game system and board game. Customize your table with textures and game boards. With support for 30+ unique units each with 30+ instances, there is plenty of room for epic dungeon encounters or galactic scale wargaming.
I used units to create the fog effect and background.
In the future, there will be a dedicated tool to edit a tabletops skybox.