Bukkit/CraftBukkit — pull request #515 by mikeprimm (2011-10-23 17:41:47+00:00)
Title: Add Block API for Sky light level and Emitted light level

These allow access to the lower-level lighting data, which can be used for both light color sensitivity (redder emitted light vs bluer sky light), as well as other light-type-sensitive functions (sky light level approximates visibility of the location from above, predicting light levels after dark or during storms, etc).

Corresponding pull in Bukkit - TBD.