Sulfur is currently used in the crafting recipe of Gunpowder, making it an essential item for crafting Ammunition and Explosives.
You can gain Sulfur by smelting Sulfur Ore in a Furnace, and you will obtain 1 Sulfur per Sulfur Ore. The Furnace burns around 2.5 Wood per Sulfur Ore smelted.
As a part of Explosives, it is the key material needed for raiding player-made structures.
Player-made houses made from Stone or Sheet Metal require 4000 Sulfur to destroy a wall or floor piece with two Timed Explosive Charges or 5600 Sulfur per wall or floor piece with four Rocket Ammunition.
Sheet Metal and Armored upgraded structures are very difficult to damage by other means meaning player-made houses are near-indestructible with the use of Sulfur's capabilities.