The Javelin is a type of ranged weapon. It is not smithable or fletchable, and can be bought only from the Ranging Guild and from the Pest Control activity archery shop. Certain monsters drop different types of javelins, however, the javelin drops are usually not very common. The attack range of javelins is 5 spaces.
Javelins were once purely members content, but were made available to non-members on the release of the Evolution of combat. They are currently the only thrown weapon available to non-members, and the only feasible one-handed ranged weapon in free-to-play. They are not sold in any free-to-play shops, however, making them only accessible to non-members via the Grand Exchange or trading with other players. Due to the difficulty in obtaining them in free-to-play, and their higher price compared to similarly leveled bows and arrows, they are not commonly used in non-members worlds. Perhaps their most common use is to kill Elvarg in the Dragon Slayer quest.