Burning Zombie
Burning mobs give off light.
Assortment of Items
Several items now emit light when dropped on the ground.
Blaze and Magma Cube
Blazes and Magma cubes naturally give off light.
Torch in Offhand
A torch in the offhand also works.
Flaming Arrows
Flaming arrows give off light.
Lava Bucket Melting Snow
By producing real light, this bucket of lava induces snow to melt.