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1 5lib/ 2 include/ 1 sccs
1 Xlir3@ 1 kvm 1 share/
1 adm@ 4 lib/ 1 spool@
6 bin/ 1 local/ 1 sqps
1 boot/ 8 lost+found/ 1 stand/
1 demo/ 1 man@ 1 sys@
1 diag/ 1 mdc/ 1 tmp@
1 dict 1 old/ 2 ucb/
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Application
XView Toolkit
Xlib
Device
X11 Server Window Manager
Figure 1-4. The software architecture of X applications
Note that using a toolkit does not preclude calling Xlib directly to accomplish certain tasks
such as drawing. In XView, graphics rendering is done most efficiently by using Xlib draw-
ing routines, for instance.
1.3 Extensions to X
Another thing to know about X is that it is extensible. The code includes a defined mecha-
nism for incorporating extensions, so that vendors are not forced to modify the existing sys-
tem in incompatible ways when adding features. An extension requires an additional piece
of software on the server side and an additional library at the same level as Xlib on the client
side. After an initial query to see whether the server portion of the extension software is
installed, these extensions are used just like Xlib routines and perform at the same level.
Among the extensions currently being developed are support for 2D spline curves, for 3D
graphics, and for Display PostScript