Hi I looked at the code of SystemNavigation and I think that this is the time to rewrite it :) I know I assemble the code from Browser and SystemDictionary at that time and we can see it. I would like also to have allClassesUsingPool: allClassesUsingPoolVariable: http://code.google.com/p/pharo/issues/detail?id=2868 In addition I would like to be able to specify the environment in which the navigation is done so that we could navigate multiple environments like the ones for bootstrapping the system we are fighting with :) http://code.google.com/p/pharo/issues/detail?id=2869 Stef