Plain Window!

I've just learnt the basics of c++ (classes, functions, pointers etc), and i want to develop my first real app with a GUI, like notepad or something.
Whats the easiest way to create a plain window.
I've just started to develop in Linux so I don't want to use MFC.
Is there a default window class in linux and whats it called.

Thanx for your help its much appreciated.

you're asking a linux question on a windows programming board...funny...

try http://ypr.34sp.com - they seem to be a bunch of linux-lovers over there :)