こんなの見つけたんだが、お前ら的にはどう?

Nana C++ Library
alpha by jinhao

Win32 (MS Windows), X Window System (X11)

http://nanaproject.wordpress.com/
http://sourceforge.net/projects/stdex/
http://www.rhinocerus.net/forum/language-c-moderated/692330-nana-free-c-gui-library-v0-1-16-released.html