X-based libraries

object-oriented framework for GUI creation

GTK (formerly GIMP ToolKit and GTK+) is a free open-source widget toolkit for creating graphical user interfaces (GUIs) targeted at Linux and specifically GNOME (though with some use in other desktop environments). It is licensed under the terms of the GNU LGPL, allowing both free and proprietary software to use it.

wxWidgets (formerly wxWindows) is a widget toolkit and tools library for creating graphical user interfaces (GUIs) for cross-platform applications. wxWidgets enables a program's GUI code to compile and run on several computer platforms with no significant code changes. A wide choice of compilers and other tools to use with wxWidgets facilitates development of sophisticated applications. wxWidgets supports a comprehensive range of popular operating systems and graphical libraries, both proprietary and free.

GUI specification and toolkit for the X Window System

Fast Light Toolkit (FLTK) is a cross-platform widget (graphical control element) library for graphical user interfaces (GUIs), developed by Bill Spitzak and others. Made to accommodate 3D graphics programming, it has an interface to OpenGL, but it is also suitable for general GUI programming.

libraries and software frameworks

Collection of software libraries and frameworks

GLX (initialism for "OpenGL Extension to the X Window System") is an extension to the X Window System core protocol providing an interface between OpenGL and the X Window System as well as extensions to OpenGL itself. It enables programs wishing to use OpenGL to do so within a window provided by the X Window System. GLX distinguishes two "states": indirect state and direct state.

X11 XToolkit Intrinsics library used to manage resources and events

GUI widget library for the X Window System

U++, formally known as Ultimate++ - is a C++ RAD framework that aims to reduce the code complexity of typical desktop applications by including all necessary toolkits into a single C++ framework. Programs created with U++ work on multiple Operating Systems and Hardware Architectures with performance without needing to write platform-specific code.

LessTif is a defunct free software reimplementation or clone of the Motif computer programming toolkit. The project aimed for full source- and binary-code compatibility with Motif. While this was not achieved, many Motif applications could run with LessTif or be compiled with it.

Xft, the X FreeType interface library, is a free computer program library written by Keith Packard. It uses the MIT/X license that The Open Group applied after the post X11R6.4 license restoration.

thumb|The XAA/EXA/UXA/SNA APIs are for the 2D graphics drivers inside the display server|X server. Note, that modern software uses direct rendering. thumb|Glamor (software)|Glamor obsoletes DDX, here with [[XWayland.]] In computing, EXA is a graphics acceleration architecture of the X.Org Server (see also X Window System) designed to replace XAA (the XFree86 Acceleration Architecture) and to make the XRender extension more usable, with only minor changes needed to adapt obsolete XFree86 video drivers written to use XAA; it was designed by Zack Rusin and announced at LinuxTag 2005 and first rel

thumb|right|200px|SunOS XView calctool thumb|500px|X Window System graphics stack

PHIGS ('''Programmer's Hierarchical Interactive Graphics System''') is an application programming interface (API) standard for rendering 3D computer graphics, considered to be the 3D graphics standard for the 1980s through the early 1990s. Subsequently, a combination of features and power led to the rise of OpenGL, which became the most popular professional 3D API of the mid to late 1990s.