Cross-platform high-level widget toolkits for C

Are there any high-level, cross-platform, and abstracted (simple to use) widget toolkits for C that are either very lightweight and fast or can be compiled fo开发者_运维知识库r other toolkits, such as Qt and GTK+?

EDIT: Most C++ libraries lack C bindings, so they will be of little (or no) help.

enlightenment enables real cross platform from Windows CE to WIndows 7, from Linux to embedded Linux, Mac OS to Mac OS X and it is leightwieght

www.enlightenment.org

All GUI toolkits have their quirks and require some time to become familiar with.

If you mean pure C, then GTK+ is the most likely choice, any of the others I'm familiar with are written in C++, so C++ is their native language binding. I have written a simple application with GTK+ in C, and once you become accustom to the container methodology for layout control it becomes quite reasonable to use. It is licensed under GNU LGPL 2.1.

One additional factor that can influence choice are licensing requirements, typically whether your usage is open-source of a particular license or a proprietary application.

wxWidgets uses a LGPL-like license to allow open source and proprietary usage.

Qt is available under various licenses, GPL, LGPL, and a non-free (gratis) commercial license, and is natively C++ binding.

My choice is FLTK (http://www.fltk.org) but neither it nor the aforementioned wxWidgets are for C. They're C++ libraries.