TargetBuffs is a project mainly written in Lua, it's free.
Addon for WoW which filters target buffs/debuffs based on target reaction and buff type
Shows target's buffs or debuffs depending on it's reaction in its own frame, buffs for hostile, debuffs for friendly.
Allows filtering buffs based on the buff type (currently just magic).
Useful for dispelling classes, priests particularly, but could be useful for shamans and paladins as well.
Options can be accessed through '/tb'.
Raine Virta (raneATkapsiDOTfi)