The X Toolkit

At a higher level, X application programmers have access to a number of different toolkits now readily available, such as XView from Sun Microsystems, InterViews from Stanford University and Andrew from Carnegie Mellon. All these toolkits are built on top of Xlib, but are not part of the X standard defined by the X Consortium and shall not be discussed any further.

This document is concerned with only one particular toolkit, known as the X Toolkit (note the upper case T in Toolkit), which is also built on top of Xlib and also conforms to the X standard. The X Toolkit consists of a set of routines, known as the X Toolkit intrinsics, often referred to as Xt, plus a set of high level user interface components, known as widgets. There are many different widget sets available that are compatible with the X Toolkit intrinsics, for example, Athena from MIT, Motif from the Open Software Foundation (OSF) and Open Look from Sun Microsystems. So, any of these widget sets together with the X Toolkit intrinsics belongs to the X Toolkit. Figure 7 provides a programmer's view of X.

 
Figure 7: The X programming interface