ASL provides peer-reviewed and portable C source libraries. The libraries are intended to be widely useful, leveraging and extending both the C Standard Library and the Boost Libraries.
a 2D graphics library, support for multiple output devices. (output targets include the X Window System, Win32, image buffers, PostScript, PDF, and SVG file output. Experimental backends OpenGL (through glitz), Quartz, and XCB.
is a layer above the existing toolkits available (Win32 API, GTK, Cocoa, ...). The result is that applications look and function like the user expects on their respective system. Mozilla Public License
port of the X Window System server to Windows. It shares the same source code base as Cygwin/X, but does not depend on the Cygwin environment or cygwin1.dll. Xming is a fully featured X11 server for Windows that is very simple to install and use.
a free user interface builder for GTK+ and GNOME interfaces designed are saved as XML, and by using the libglade library these can be loaded by applications dynamically as needed. (Glade can also generate C code)
a high-level multi-platform, thread-safe C/C++ windowing and graphics library built upon a fast, low-level graphics kernel. (new feature is FGX - dynamic GUI via XML file aka XUI file format)