In 2004 Bacon et al. showed that tracing GC and ref-counting GC are special cases of a more general framework, and that it is possible to combine them to get th

In 2004 Bacon et al. showed that tracing GC and ref-counting GC are special cases of a more general framework, and that it is possible to combine them to get the benefits of both. See "A Unified Theory of Garbage Collection" here: http://www.research.ibm.com/people/d/dfb/publications.html http://www.research.ibm.com/people/d/dfb/publications.html Scholar cluster: http://scholar.google.com/scholar?q=bacon+unified+theory+garbage+collection http://scholar.google.com/scholar?q=bacon+unified+theory+gar... Incidentally, it is not even remotely true that reference counting is more efficient than tracing GC in all cases.