Native Menus and Menubars
Tk 8.0 has a native menubar mechanism. You define a menu and associate it with a toplevel. On the Macintosh this menu appears along the top of the screen when the window is activated. On Windows and UNIX the menubar appears along the top of the window. This facility is described on page 397.
Tear-off menus now track any changes to the menu they were created from. As part of this, the -transient attribute was replaced with a -type attribute.
You can create multicolumn menus with the -columnbreak attribute.