Forge Halo 3

Forge is a tool made for players to insert game objects into the existing maps. Bungie stated this is more of a game type than a tool. Almost all weapons, vehicles, and interactive objects can be inserted into the maps and moved around. You can do anything from placing large number of your favorite vehicles or from stripping the map clean of many objects. Forge will also allow you to add objects in real time. You will be able to save custom setups and share and download them using the File Sharing feature.