Hi folks: Sometimes, my Pharo images grows a lot. Size like 80MB or similar. Marcelo Cortez gave me a couple of changes (fileouts) that make my images go back to their original size or similar. For example, it was tasted in a 87 MB and after this changes and this stuff, it become in 24 MB. The same with another one from 65M to 35M. If you have a big Pharo image, save a copy and do this tests: 1) File in all the changes I attach. 2) Go to a workspace and evaluate: OBDPAbstract reinitAllCache. LocalSends allInstances first initialize. EventManager resetMap. Smalltalk garbageCollect. Did this make your image too much smaller? When I evaluate SystemNavigation default obsoleteBehavio size I get a a number of 3 digits. Perhaps it is a matter with the OB. I guess it generates dependences while you are developing a class and it creates on the fly an obsolteClassXXX when there is something that doesn't exist. Then they are processes and they are never garbage collected. When SmalltalkImage tries to fix the obsoletes delegates to the literal frames of the compiled methods so that to search references to the obsoletes. But references were not gone because they weren't garbage collected. The same method finishes with error if the obsoletes > 0. Does anyone has a comment for this? I tried to do my best to write in English from what Marcelo told me and from what I can understand from the changesets. Best, Mariano