It is not impossible, it is quite simple, just get the list of installed packages and subtract from it the list of packages on the default system installation.
** Changed in: apt (Ubuntu) Status: Invalid => Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/90228 Title: Impossible to list only user installed packages -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs