X Toolkit Intrinsics
（重定向自X Toolkit）
![](/Images/godic/202502/21/Xlib_and_XCB_in_the_X_Window_System_graphics_stack.svg0604.png")
X Toolkit Intrinsics (also known as Xt, for X toolkit) is a library that implements an API to facilitate the development of programs with a graphical user interface (GUI) for the X Window System. It can be used in the C or C++ languages.
The low-level library Xlib is the client-side implementation of the X11 protocol. It communicates with an X server, but does not provide any function for implementing graphical control elements, such as e.g. buttons or menus. The Xt library provides support for creating and using graphical control elements, but does not provide any itself. Instead graphical control elements are implemented by other libraries using Xt, such as Xaw and Motif.