FLTK (pronounced "fulltick") is a LGPL'd C++ graphical user interface toolkit for X (UNIX), OpenGL, and Win32. FLTK was designed to be small and modular enough to be statically linked, but also works fine as a shared library. FLTK also includes FLUID, an interactive user interface builder program. This is version 1.3. From the FLTK website: FLTK 1.3 is the current stable development branch based on FLTK 1.1.10. It adds internationalization, UTF-8 (Unicode), and printing support, Doxygen based documentation, and several new widgets including Fl_Native_File_Chooser, Fl_Table, and Fl_Tree_View.