>yes but I intended: "you can have your own kind of gc, because ruby >garbage collection does not really determine the behaviour of a >program". >If you have 3-color generational gc or simple reference counting with >cycle detection I think that nothing will change for the final user. >Anyway, I may be wrong. > > > > I think changing to a reference counting GC system would change the behaviour of the program, since it would change when an object is collected. I know that this subtlety has caused problems for people moving from CPython (Which uses reference counting) to Jython (which uses mark and sweep) -- Mark Sparshatt