I havn`t finished learning C++ but I was wondering, what should I use to make GUI applications(libraries etc), I use Windows and Linux and would like one that works on both. Thnak you
You might want to consider Qt. It is a very common, easy to use, and high quality library for making GUIs accross a large number of platforms (Windows, Mac, Linux, Embedded Linux, Android, Blackberry, etc...). It also has its own IDE that comes with it, complete with a form designer for your GUI.
If you don't really like Qt, there is also wxWidgets (which is now version 3, I believe). This seems to me to be a lower-level library: It takes more to get the same amount done as Qt, though you can get more control more easily. However, you rarely need that much control: Think of wxWidgets as a sort of a wrapper around things like xlib or WinAPI.