A fairly simple addon that announces when units are detected, removed, health/shields/absorb, and casting states change.
The goal for this use is to allow multiple addons to share the same single scanning process by having one addon control the speed and information output.

Events fired:

CombatEvents_Loaded
      used by addons checking to ensure CombatEvents is loaded
            tEventArgs,
                  version, number

CE_UnitCreated
      Unit Creation event with health, shields, absorb and casting data
            tEventArgs,
                  unit, unitObject
                  unitId, unitId
                  name, string
                  type, string
                  isCasting, boolean
                  health, table (same data as CE_UnitVitalsChanged)
                  shield, table (same data as CE_UnitVitalsChanged)
                  absorb, table (same data as CE_UnitVitalsChanged)
                  cast, table (same data as CE_UnitCastStateChanged)

CE_UnitDestroyed
      Unit Removal event with unitId
            tEventArgs,
                  unitId, userId

CE_UnitVitalsChanged
      Unit Vital event, returns health, shields absorb tables with current and max values if changed
            tEventArgs,
                  unit, unitObject
                  unitId, unitId
                  health, table (current, max)
                  shield, table (current, max)
                  absorb, table (current, max)

CE_UnitCastStateChanged
      Unit Casting event, returns is_casting and spell details at cast time and cast end
            tEventArgs,
                  unit, unitObject
                  unitId, unitId
                  is_casting, boolean
                  type, enum
                  name, string
                  pct, float
                  duration, float
                  elapsed, float

Combat Events