This is different if you're talking about a console or a terminal emulator (in a windowing system). In a console you might have a console driver, while in a wi

This is different if you're talking about a console or a terminal emulator (in a windowing system). In a console you might have a console driver, while in a windowing system you might have a text renderer. The text renderer can be a library that is still above the level of the windowing system, or in some windowing systems it can be a functionality provided by the windowing system itself. For an example, see http://www.pango.org/ http://www.pango.org/. (But note that there are other options for handling this layering. There is no principle of operating system design that says that this task absolutely has to be handled at one particular layer or another.)