You've probably dealt with X resources before, like the following ones
from an OLC stock answer:

xterm.Foreground: white
matlab*reverseVideo: false	    ! matlab windows in "reverse video"
emacs*Font: 8x13                    ! emacs with 8x13 font, 80 columns
emacs*geometry: 80x48+0+0	    !   wide, 48 columns high

Often, the forms entries take on are:

	program*resource: value
	program.resource: value

In widget programming this concept is expanded to

	program.widgetname.resource:	value
	program.widgetname1.widgetname2.resource:	value
	program.widgetname1.widgetname2.widgetname3.resource:	value

etc. wherewidget3 is inside widget2 is inside widget1.  You could
abbreviate that last one as

	*widgetname3.resource:	value

The * acts as a wildcard.  If you peruse the Motif man pages, you'll see
that widgets have resources that control just about everything about
them.  Their colors, fonts, position within other widgets.

A great example of a file with this type of resource is
	 /usr/athena/lib/X11/app-defaults/Olh

The Athena on-line-help program is a motif application.  It has lines in
it like:

*banner.topAttachment:          ATTACH_FORM
*banner.leftAttachment:         ATTACH_FORM

You could put that second one in your .Xresources file and change it to

*banner.rightAttachment:         ATTACH_FORM

and olh would show up with its banner right-justified.  You see,
app-defaults files are just a special kind of X resource file.  With X
resources, you can totally specify the layout of your user interface.
The only thing you can't normally do in X resources are specify what
widgets are created.

But with the Widget Creation library, you can.  Today we'll look at a
very short, simple motif program called Mri that pops up a user
interface specified entirely in X resources.  In the next class you'll
start writing C to put functionality behind the interface.