We describe a distributed garbage collector protocoltargeted for uncooperative distributed object orientedsystems. The protocol has been implementedon distributed Lisp system and a few performancemeasurements are discussed. Since this implementation,we have refined deeply the protocol to addressnon FIFO channels. A new reference model is proposedalong with the protocol to improve invocationefficiency.1 IntroductionOur research is concerned with distributed garbagecollection