People with VMS experience, or who remember TOPS-20 often miss these systems' file-versioning facilities. Opening an existing file for write or deleting it actually renamed it in a predictable way including a version number; only an explicit removal operation on a version file actually erased data.
Unix does without this, at a not inconsiderable cost in user irritation when the wrong files get deleted through a typo or unexpected effects of shell wildcarding.
There does not seem to be any foreseeable prospect that this will change at the operating system level. Unix developers like clear, simple operations that do what the user tells them to do, even if the user's instructions could amount to commanding “shoot me in the foot”. Their instinct is to say that protecting the user from himself should be done at the GUI or application level, not in the operating system.
