Format
A << B
Cause the value B to be output to any players connected to mobs specified in A.
B may be an image, sound, or text. A may be a mob, the whole world, or any list containing mobs.
usr << "Hi, [usr.name]"
view() << "To all in view"
world << "Hi everybody!"
usr << 'giggle.wav'
view() << image(/obj/Fireball,usr)