MS Office’s fully customisable toolbars, complete with built-in icon editor.

…ripped out when the Office Ribbon was introduced in 2007; the now-limited customisation is now considered an improvement because of the IT support problems caused by users messing up their own toolbars.

I mean, yes; but that’s what Group Policy is for! And the removal of the icon editor is just being downright mean to bored school kids.