Welcome to the ``tip of the week'', a pithy kickshaw provided on a
sometimes weekly basis.

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		Netscape Considered Harmful

(Netscape Navigator and related names are trademarks of the Netscape
Communications Corporation.  The Corporation is welcome to keep them.)


1.  Please Exit Netscape
------------------------

Here and below, ``Netscape'' is shorthand for the ``Netscape
Navigator'' Web browser.

If you quit an X Windows session while a copy of Netscape is 
running, your Netscape program will not necessarily exit nicely,
or exit at all.  These unattached processes can consume significant
amounts of memory and CPU time, so please, please kill off any
copies of Netscape *before* you quit X Windows.


2.  Colormaps
-------------

X Windows handles onscreen colors by using a table to manage the
assignment of pixel colors to requested colors (many more colors
can be described than realized onscreen, at least with most hardware).

X Windows applications contend with one another for these color
assignments and you may notice that document viewers such as xdvi, xv,
Acroread, or Ghostscript, as well as Web browsers will sometimes look
vague or even strange in color and sharpness.

If you have this trouble (typically, an xdvi session looks awful) then
you should kill off as many graphical, color-using applications as
possible and restart your document viewer.  In particular, kill off
any sessions of Netscape or other graphical Web browsers.


3.  The disk cache
------------------

Netscape and some other Web browsers speed up access to documents by
tucking private copies away in a ``disk cache,'' typically found in
the .netscape/cache subdirectory of your home directory.  This device
is useful in reducing access times and loads on Web servers, but it
can lead to trouble in a couple of ways.

(a)  If you are using Netscape to view a document you are revising
then you may have to be rather forceful to get the browser to display
the new rather than the old version of your document.

(b)  The disk cache can use up quite a bit of disk space.

Use the Options/Network Preferences menu item from the Netscape
toolbar to exhibit a popup which will allow you to clear both the
memory and disk caches for Netscape.  This will not damage your
bookmarks or other files, and may be necessary to solve some
annoying problems with the browser.

math.ufl.edu has a script which cleans out disk cache files for Netscape
periodically, but you may still need to flush the cache by hand.

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The title of this Tip echoes a famous paper by Edsger W. Dijkstra,
``Goto Statement Considered Harmful.''  Both the argument and the
title of that paper are classics in computer science, and variations
on that title are often used as attention-getting devices.

Past Tips of the Week are found in /depot/documentation/tips/.  They
may also be consulted through the Documentation/Online Help menu item
of the window system's main menu or through Info mode in the Emacs
editor.


						   cws@math.ufl.edu

Subject:	Netscape considered harmful