Yes it is. The initials stand for "long lasting paper developer". It has an incredibally long life in trays and in bottles between uses. It can be used as a replenishable developer as well, and comes in powder or liquid(most prefer powder). The great point is tonal control via dilution without changing developing time. Mix 1+3 or 4 for warm tone or 1+1 or 2 for cool tone.
Originally Posted by Daily Alice