Initially this issue was about implementing a startfile-equivalent on posix.  But if you have to add a gui option to startfile to not lanuch a GUI, and your real goal is a consistent way to launch non-gui programs on posix, then I don't see that this is about implementing startfile, and the enhancement should *definitely* not go in os.

Setting that aside for a moment, let me say something about the wrapper argument.  There *is* a lot of compatibility code in os.  We do have to jump through hoops to get posix equivalent functionality on Windows.  So doing the reverse to get windows-equivalent functionality on posix would seem fair turnabout.

However, it is also true that those hoops we jump through for windows involve calling Windows APIs (the equivalent of the posix system calls we are wrapping).  So while the hoops aren't necessarily all that "thin", they are wrappers around APIs at the OS level (thus the name of the module).  In this case the hoops are not system calls.  So even disregarding my initial comments above, while I don't think the argument is quite as clear cut as Éric does, I do think in this case the code, which is *not* operating at the C API level, does not belong in OS.

Finally, I'm still against shutil.open as the name.  It does not suggest to me that an application is being run.  (Neither does 'startfile', by the way).