A little more. I made an experiment with compressing a method sources into trailers. (you need to file in a changeset (trailer-fixes-extensions.1.cs ) http://bugs.squeak.org/view.php?id=7428 What i did is: CompiledMethod allInstancesDo: [:m | m dropSourcePointer ] It takes a while (compressing sources). A more faster way is to do same in workspace: old := CompiledMethod allInstances select: [ :each | each trailer hasSourcePointer ]. new := old collect: [ :each | each copyWithTrailerBytes: (CompiledMethodTrailer new sourceCode: each getSource) ]. old elementsForwardIdentityTo: new. Before: Image size: 26,192,916 bytes After: Image size: 33,348,596 bytes difference: 7,155,680 bytes. But this means, that your image doesn't have to use .sources file, which is 17,584,724 bytes long as well as .changes 11,745,139 bytes long.. of course, stripping like this, will leave you without method stamps.. :) -- Best regards, Igor Stasenko AKA sig.