Hi, the current Pharo cannot deal very well in situations when you want to run multiple instances from one image file, especially on Windows, which complicates the setup of parallel applications. It is not able to work reasonably on read-only file-systems too. That's why I did the next attempt to improve this functionality of the system. In summary: - the image can be executed with --readOnlyMode image argument - the basic system tries to survive such limitation. The changes file is in read-only mode and new sources are installed into compiled methods directly, Ombu does not save content, Playground does not save cache etc. - PharoDebug.log and placeholder files on Windows are not created - the limitation is only on image-level so it is easy to bypass it. - the presence of the old file streams makes everything uglier and messier We have an open PR for this issue: https://github.com/pharo-project/pharo/pull/3837 Comments and reviews are welcome. -- Pavel