Throw is a command anyone can use that throws a held weapon at someone. It costs 30 gp and does not need to be learned. It deals a fair bit of damage, and works best with throwing weapons. How effective throwing weapons are is listed in successful judge.
Some knife sheathes (knife belt holds 10 knives, wolfskin armbands 2 each, some boots hold 2) allow a hurl command, which is like throw but automatically draws the weapon from the sheath if you have an empty hand.
Throwing weapons lose condition quite quickly. Whether this is because they have low maximum condition, because low skills make them take damage, or just because is unknown. Be prepared to fix them frequently. Also, a thrown weapon that hits will end up in the target's carried inventory. Note that recovering the weapon from the corpse will trigger any wards on it.
Rumor has it that guildmaxed javelins strike for 1k damage when thrown. There are no hurl-sheathes for them.