Command and Conquer Tiberian Sun
BattleSun is an editor for CnC: Tiberian Sun (and TS: Firestorm). It helps with editing scenario files (battle.ini and battlefs.ini) which you must edit in order to play your own singleplayer maps.
BattleSun 2 Editor is an editor for CnC: Tiberian Sun and TS: Firestorm. It helps with editing scenario files, the battle.ini and battlefs.ini, which you must edit, in order to play your own single player maps.
This is the program of preference for most mappers that's proved itself time and time again to be one of the better mapping programs out there.