1. Is there a wiki entry about the GC somewhere that provides advice about how to tune the GC using #setGCParameters? 2. If I have two objects with accessors: Object subclass: #ObjectA instanceVariableNames: 'objectB' classVariableNames: '' poolDictionaries: '' category: 'Temp' Object subclass: #ObjectB instanceVariableNames: 'objectA' classVariableNames: '' poolDictionaries: '' category: 'Temp' and create an instance of each in a workspace and then set them up: |a b| a:=ObjectA new. b:=ObjectB new. a objectB: b. b objectA: a. and close the workspace then those instances of ObjectA & ObjectB will never be garbage collected, correct? Its my understanding that I'd need to nil out the instance variables of both instances to have them GCd as they both refer strongly to each other. Is that right? 3. How can I learn when an incremental or full GC run will happen? Is it dependent upon on the size of new or old memory or the overall size of the image or ... ? It seems like putting a #halt in a random spot could easily lead to a stuck image. Thanks for your help Paul