Make Winforms application for Windows,Linux(Ubuntu), and OSX

[nickkorta]

I want to make a application that runs on Windows, Linux, and OSX.
For Linux my IDE is QT and I run both Ubuntu and Mint.
For windows I am using Windows 8 and Visual Studio and QT.
I don't have any apple devices on me but My school has some.

I was wondering if there is a library or something I can use. Iv created Win forms asps before but only exclusively for Windows. I of course want to use C++.

Thanks

[modoran]

There is Qt or wxWidgets, both of them are very good:
http://www.wxwidgets.org/
http://qt-project.org/downloads

[nickkorta]

Thanks