those windows on the left-hand side of Mozilla; how to do it?

["Edward A. Falk" <falk efalk org>]

Hi all; I don't even know the name of this thing, but I've seen a
number of applications (e.g. Mozilla) that have an interesting way of
stacking windows on the left edge of the application.

Let me describe it:  The left edge is maybe 1 or 2 inches wide.  It
contains a number of buttons that run the full width of the window and
are just tall enough to contain a text label.  Clicking on one of those
buttons causes it to replace itself with a container widget containing
other things.  Clicking on another button causes the open one to close and
the new one to open in its place.

Let me try some ascii art:

	button
	column
	   V
	+-------+-------------------------------+
	+-------+				|
	+-------+				|
	|	|				|
	|	|				|
	| open	|				|
	|	|	main			|
	|window	|				|
	|	|	application		|
	|	|				|
	|	|	window			|
	|	|				|
	|	|				|
	|	|				|
	+-------+				|
	+-------+				|
	+-------+				|
	+-------+				|
	|	|				|
	|	|				|
	+-------+-------------------------------+

	after user clicks a button:

	+-------+-------------------------------+
	+-------+				|
	+-------+				|
	+-------+				|
	+-------+				|
	|	|				|
	|	|				|
	|an-	|				|
	| other	|	main			|
	|	|				|
	|window	|	application		|
	|	|				|
	|	|	window			|
	|	|				|
	|	|				|
	|	|				|
	+-------+				|
	+-------+				|
	|	|				|
	|	|				|
	+-------+-------------------------------+

Mozilla is slightly more elaborate than this, but I'm describing what
I'm after.

Any suggestions on how to achieve this?
Mozilla is slightly more elaborate than this, but I'm describing what
I'm after.

Any suggestions on how to achieve this?

	-ed falk