The only time I have used a GC on our C code, is Purify (A C checking tool, that find leaks). Doea anyone have some ideal how its speed comparse to the speed of a conservative GC. I find that Purify, take a long to time find leaks, much longer then we could put up with from a GC, but using a conservative GC would be nice. Ian Ringrose ianr@lsl.co.uk