
                              XScreenSaver

            a screen saver and locker for the X window system
                            by Jamie Zawinski

                     http://www.jwz.org/xscreensaver/

To build on Unix:

  -  ./configure
  -  make
  -  make install

The `configure' shell script will attempt to figure out which options are
appropriate for your system, and will create config.h and the various
Makefiles for you.  Run `configure --help' to see how to override these
choices, or to specify things like the default installation directory.
The file `INSTALL' gives a general overview of use of these sorts of
configure scripts (those generated by the GNU autoconf system.)
The most important hint is probably this:

     ./configure --with-motif=/opt/Motif --with-xpm=/usr/local

To build on VMS, see README.VMS.

If you think you've found a bug, please let me know!  No bug report is too
small.  But first, please read the enclosed `README.debugging' file to find
out what kind of information would be most helpful to include in your bug
report.

Getting Started:

You can try out xscreensaver like so:

	xscreensaver &
	xscreensaver-command -demo

After a few seconds, the screen should go black, and a dialog box should
appear in the upper right corner.  This is "Demo Mode".

Note: unlike `xlock', xscreensaver has a client-server model: the
`xscreensaver' process is a daemon that runs in the background; it is
controlled by the foreground `xscreensaver-command' program.

xscreensaver has an extensive manual -- please read it!

                              ============

The xscreensaver daemon waits until the keyboard and mouse have been idle
for a period, and then runs a graphics demo chosen at random.  The demo is
terminated as soon as there is any mouse or keyboard activity (or, in
locking mode, when the proper password is typed.)

It is trivially easy to add new display modes to xscreensaver: any program
which can be invoked in such a way that it draws on the root window of the
screen can be used as a screensaver.  You just change a resource setting --
there's no need to recompile or reinstall anything.

                              ============

Along with the xscreensaver daemon itself, this package also includes
numerous graphics hacks for use as screensavers.  There is nothing magic
about these: they are just programs that draw on the root window.

More than 80 such programs are included.  For details, see the xscreensaver
web page, or the enclosed manual pages.  There are also some helpful hints
on customization in the xscreensaver app-defaults file (normally installed
in /usr/lib/X11/app-defaults/XScreenSaver.)

The latest version of xscreensaver is always available on the web at
http://www.jwz.org/xscreensaver/.

                              ============

Changes since 2.33:   * Fixed a bug that was making `pipes' generate way too
			many valves.  Made the viewpoint in `pipes' be selected
			randomly instead of always being -10 degrees.
		      * Fixed a bug in the XSHM code, in the case where the
			server supports the XSHM extension but is not the same
			machine as the client.
		      * Made `rd-bomb' default to taking up the whole screen.
		      * Made it not try to do fading/unfading if no PseudoColor
			visuals exist.
		      * Initial attempt at supporting VT-locking (doesn't work
			yet.)
		      * Eliminated the `captureStdout' resource; now
			`captureStderr' controls both streams.
		      * Added `-capture-stderr' and `-no-capture-stderr'
			command-line arguments.
		      * Added `glplanet' hack.
		      * When a hack is selected with `xscreensaver-command
			-select', that hack will be used until further notice
			(until the saver turns off, or another activation
			command is issued.)
Changes since 2.32:   * Made `xscreensaver-command' print error messages:
			the xscreensaver daemon now responds to ClientMessage
			events by writing a response message on a window
			property, instead of just writing to its stderr.
		      * Made the ~/.xscreensaver file be automatically reloaded
			when the file date changes.
		      * The password dialog and splash screen no longer depend
			on Motif or Athena.  This should clear up a number of
			focus problems, and is the first step on the path
			toward moving all of the Motif/Athena/whatever code
			out of the xscreensaver daemon, and into external
			processes.
		      * Don't complain about LessTif 0.86 any more, since the
			new password dialog makes that problem go away.
		      * Configure tweaks for Irix 6.5, SunOS 5.something.
		      * New `-reflect' option to `distort'.
Changes since 2.31:   * Added reading and writing of a ~/.xscreensaver file,
			so that the Preferences panel can save its settings.
		      * New version of `rubik'.
		      * Added `-select N' argument to `xscreensaver-command'.
		      * Oops, left out some of the `bubbles3d' files...
Changes since 2.30:   * The cursor was invisible in the password dialog. Fixed.
		      * Made configure warn against MesaGL 2.6.
		      * Fixed X error at startup when using non-default visual.
		      * New version of `crystal', `ant', and `atlantis' from
			xlockmore.
		      * New hack, `bubble3d'.
		      * Added some new modes to `bsod'.
Changes since 2.29:   * Changed the order in which -lSM and -lICE are linked
			to be after Motif instead of before (Lesstif on Irix
			needs this.)
Changes since 2.28:   * Work around a bash bug in configure.
		      * Tweaked HPUX paths again.  FTSOHPUX.
		      * Made configure recommend against LessTif 0.86, due
			to a bug in that version that causes a security hole
			in the screen locking code.  LessTif 0.87 will fix it.
		      * Made all of the `--with' options to `configure' accept
			a directory option as well (so that --with-motif=/FOO
			will add -I/FOO/include -L/FOO/lib).  I believe this is
			the Configure Party Line of how do to such things.
		      * Fixed a bug where the mouse was left un-grabbed
			after the first time the graphics hack was changed
			(simplified all of the mouse-grabbing logic.)
		      * Maybe possibly perhaps made `vidwhacker' really not
			leave stray xv windows around.  This time for sure.
		      * Added a new erase mode (random dots fizzling out.)
		      * Added `-prefs' argument to `xscreensaver-command',
			that brings up the Preferences dialog directly (it
			seems that nobody ever noticed the `Preferences' button
			on the Demo Mode dialog, maybe this will help.)
		      * Added a splash screen.  Turn it off with *splash:false.
Changes since 2.27:   * Better macsbug text in `bsod'.
		      * New version of `distort' with many new modes.
		      * Plugged a leak in `coral'.
		      * Tweaked configure for HPUX.
		      * Removed some compiler warnings.
		      * More consistent usage of stderr versus stdout.
		      * More diagnostics should an X error occur.
		      * Fixed a possible crash in SGI-specific unfading code.
Changes since 2.26:   * Improved version of `distort'.
		      * Made `lament' compile against OpenGL 1.0 (though it
			still requires 1.1 to work properly.)
		      * Updated my email address and home page.
Changes since 2.24:   * Improved motion in `rd-bomb'.
		      * Added XSHM (shared memory extension) support to the
			`distort', `interference', `moire', `rd-bomb', and
			`swirl' hacks, which speeds them up a bit.
		      * Added `lament' hack.
Changes since 2.23:   * Tweaked the order of the -L options again.
		      * Cleaned up configure's `--help' message.
		      * Added `kumppa' hack.
		      * Smarter maze-solving algorithm in `maze'.
		      * Took `xlyap' out of the default list of hacks, since
			it's just incredibly buggy (and slow.)  Maybe someday
			someone will fix it...
		      * Added `distort' hack, but didn't add it to the default
			list (yet) because it's still too slow.
		      * Made the Athena demo dialog look more like the Motif
			version; it has a text-entry field now, too.
		      * Made the Athena password dialog echo asterisks, like
			Motif does, instead of using a flyspeck font.
		      * Some random configure tweaks.
		      * Added a `timestamp' resource that makes the `-verbose'
			messages include the time at which they were printed.
Changes since 2.22:   * The fix for SGI's ``scheme'' nonsense broke things, and
			let the user's "*background" resource show through.
			Fixed it in a different way.
Changes since 2.21:   * Added support for the DPMS server extension (Display
			Power Management System.)
		      * Made configure advertize the `--enable-subdir' option a
			little more, since that seemed to cause some people
			stress.  Also, made that directory be built into the
			xscreensaver executable, as a hardcoded prefix to
			$PATH.  (Might help, shouldn't hurt.)
		      * Made configure prefer the two-arg gettimeofday to the
			one-arg version, since AIX doesn't have any prototypes.
		      * Made it work with Xaw3d (the 3D Athena library.)
		      * Made `make install' create directories as necessary.
		      * New version of lmorph from Sverre.
		      * Added `crystal' and `discreet' hacks from xlockmore.
		      * Added a new mode to `bsod'.
Changes since 2.20:   * Made `xscreensaver-command -time' use different words.
			(It now describes the two states as "screen blanked
			since..."  and "screen non-blanked since..." instead of
			"active since..." and "inactive since..." which a lot
			of people interpreted as meaning the opposite of what
			was intended.)
		      * Improved some error messages, in the hopes of making
			the distinction between the xscreensaver and
			xscreensaver-command programs more obvious.
		      * Rewrote (and reorganized) parts of the xscreensaver and
			xscreensaver-command manual pages.
		      * Renamed xscreensaver's `-lock' command-line option to
			be `-lock-mode', to avoid confusion with the `-lock'
			option to xscreensaver-command, which does a totally
			different thing.
		      * Removed xscreensaver's `-demo' command-line option for
			a similar reason; use `xscreensaver-command -demo'
			instead.
		      * Disabled SGI's ``scheme'' nonsense in a better way than
			fully-qualifying the background colors in every single
			hack.
		      * Fixed some other minor cosmetic problems when *sgiMode
			is turned on.
		      * Fixed an X error in `bsod -root' (how ironic...)
Changes since 2.19:   * Fixed a bug that caused the mouse to sometimes not be
			grabbed properly (meaning the window manager menu could
			pop up over the demo-mode display.)
		      * Fixed a bug that made the stderr output sometimes get
			printed twice.
		      * Fixed a bug that made the demo-mode scrollbar move too
			fast.
		      * Protected against a possible buffer overflow.
		      * Made `vidwhacker' not leave stray xv windows around.
		      * New version of `ant' so that Bagley doesn't calve.
		      * Make configure on AIX get XShm from the right library.
Changes since 2.18:   * One file was missing from the tar file.	 Fixed.
Changes since 2.17:   * Oops, atlantis wasn't being built by default.  Fixed.
		      * Added `epicycle' hack.
		      * Added `interference' hack.
		      * Added `truchet' hack.
		      * Added `bsod' hack.
		      * Added some new modes to `vidwhacker'.
Changes since 2.16:   * Added a -window-id argument to most hacks, so that they
			can draw on arbitrary externally-provided windows.
		      * Synched with xlockmore 4.11a01.
		      * Added `flow' hack.
		      * Added `atlantis' GL hack.
		      * Renamed `puzzle' hack to `jigsaw', since xlock already
			had a different mode called `puzzle'.
		      * Made it self-configure properly when Motif 2.1.0 is
			being used (requires -lXp now, sigh...)
Changes since 2.15:   * Made `flag' able to do XPM images.
		      * New look for the xscreensaver logo (`xroger').
		      * Fixed compilation error on Suns with adjunct passwords.
		      * Got multi-architecture builds working again.
		      * Some configure tweaks for building on HPUX and Solaris.
		      * Fixed bug in decayscreen.
		      * Fixed typo in passwd.c.
		      * Made `cynosure' not die when colormap is full.
Changes since 2.14:   * Added `cynosure' hack.
		      * Added `moire2' hack.
		      * Tweaked `erase.c' some more.
		      * Made unfading a bit smoother.
		      * Added `vidwhacker' hack (not installed by default.)
		      * Added `stairs' hack.
		      * Split `escher' into `cage' and `moebius', as per
			xlockmore.
		      * Changed subprocess handling to use sigaction() instead
			of signal() if it's available (this is necessary for
			SCO but should work fine on other systems too.)
		      * Various other tweaks.
Changes since 2.13:   * Better fix for the Motif drag-and-die lossage.
		      * Put in some kludges to work around a LessTif bug.
		      * XScreenSaver is known to work with LessTif 0.82 now.
		      * Made fading work on high-end SGI video hardware.
		      * Fixed another SGI-specific bug in screen grabbing;
			will the madness never cease?
		      * Fixed another crash in `xlyap'.
Changes since 2.12:   * Made `decayscreen' do directions other than down.
		      * Improved `puzzle'.
		      * Fixed a crash in `xlyap'.
		      * Added CDE info to the man page, removed `cde.txt'.
		      * Configure tweaks for Zippy.
		      * Turned off the signal handling in `bubbles' because
			it was sometimes failing to die.
		      * Added `hacks/xscreensaver-sgigl.c' to make it possible
			to run SGI's ElectroPaint hack (/usr/demos/bin/ep)
			with xscreensaver.  Finally!
		      * Fixed a buffer overrun in the locking code that some
			wily, malicious cracker must have slipped in.
		      * Disabled Motif drag-and-drool in the dialog box
			buttons, since it's broken in some old versions of
			Motif.
Changes since 2.11:   * Added `README.debugging'.
		      * Added `puzzle' hack.
		      * Added `xlyap' hack.
		      * Added `default-n' as a visual name, so that one can
			have -install on by default, but turn it off for
			certain poorly-behaved hacks (like xv.)
		      * Added support for grabbing frames of external video
			(on SGI) to the screen-grabbing hacks (decayscreen,
			slidescreen, slip, blitspin, and puzzle.)
		      * Improved look of tiles in `slidescreen'; fixed its
			color allocation problem.
Changes since 2.10:   * Tweaked `blitspin', added it to the default list.
		      * Added `lissie', `mountain', `triangle', `worm',
			`rotor', and `ant' from xlockmore.
		      * Updated `sierpinski', `galaxy', and `lisa'.
		      * Thickened the lines in `braid' and `lmorph'.
		      * Updated VMS makefiles.
		      * Renamed `fract' to `vines'.
		      * Added `xjack' hack.
		      * Made a few more hacks use erase.c, and added a few
			more wipe styles.
		      * Fixed compilation problem with Sun's version of OpenGL.
		      * Added ability to use sigaction() instead of signal()
			to work around a SCO kernel bug.
Changes since 2.09:   * Fixed colormap bugs in `rd-bomb'; sped up `coral'.
		      * Configure tweaks for *BSD.
Changes since 2.07:   * New hacks `rd-bomb' and `coral'.
		      * New version of `maze' with some new algorithms.
		      * New colorized version of `rocks'.
		      * Fixed a bug in qix on 64-bit machines.
		      * Fixed a bug in the -time option.
		      * Fixed a bug in configure related to LessTif.
Changes since 2.06:   * Minor header tweaks in windows.c and flag.c.
		      * Made multi-architecture ($VPATH) builds work properly.
		      * Merged new GL stuff from xlockmore (rubik, morph3d.)
		      * Fixed intermittent crashes in `imsmap' and `munch'.
		      * Added `fadeplot' hack from xlockmore.
Changes since 2.05:   * Merged in VMS support from Patrick Moreau.
Changes since 2.04:   * Fixed a MIT-SCREEN-SAVER-related crash, and tweaked
			configure to detect the extra-random -Xss library.
Changes since 2.03:   * HP configure tweaks.  Detect and warn about LessTif.
		      * Fixed low-color behavior of `goop', `pyro', `starfish',
			`greynetic', `flame', `halo', and `moire'.
Changes since 2.02:   * Fixed flicker in `pipes'.  Fixed 3d in `bouboule'.
		      * Added `munch' hack.
		      * Added basic dependencies to the Makefile.in files.
Changes since 2.01:   * Fixes for compiling with the MIT saver extension.
		      * Made the yow/fortune program be a configure option.
		      * Various configure tweaks.
Changes since 2.00:   * Added `goop' and `starfish' hacks.
		      * Added colomap cycling to `halo'.
		      * Made `attraction' use the new colormap allocator.
		      * Added better $PATH diagnostics.
		      * There was a bug in frand!  Color selection should be
			much improved now.
Changes since 1.34:   * Converted to use `configure' instead of `imake'.
		      * ANSI C is now required.
		      * Added Kerberos locking support, from Nat Lanza.
		      * Made the stderr text use overlay planes, if possible.
		      * Reworked the xlockmore compatibility stuff again.
		      * Added `gears', `superquadrics', `escher', `pipes',
			and `sproingies' hacks (depend on OpenGL.)
Changes since 1.33:   * Fixed some bugs, made fading be a little smoother.
Changes since 1.32:   * Made it work with multi-headed displays.
		      * Generalized sub-process management (Unix sucks!)
		      * Added interactive mouse frobbing to Julia.
		      * Added (untested) support for HPUX shadow passwords.
		      * Made normal non-shadow passwords be checked if the
			shadow passwords aren't accessible for some reason.
Changes since 1.31:   * Removed *colorPrograms and *monoPrograms resources:
			made it possible to specify the desired visual on a
			per-hack basis.
		      * Cleaned up / restructured the driver: no more globals.
		      * Made the Motif and Athena dialogs share more code.
		      * Probably fixed some Athena colormap-installation bugs.
		      * Fixed screen grabbing (cmap) on SGI 12-bit PseudoColor.
		      * Fixed divide-by-zero in bright random colormaps.
		      * Added an improved version of xlock's `flag' hack.
		      * Made unfading work better, and not flicker on SGIs.
		      * Added `sphere', `forest', `lisa' hacks from xlockmore.
		      * Added (untested) support for SunOS Adjunct passwords.
Changes since 1.30:   * Improved colors and colormap cycling of many hacks.
		      * Cleaned up xlockmore compatibility layer.
		      * Made `blitspin' able to grab an image off the screen.
		      * Ported `swirl' and `bouboule' hacks from xlockmore.
		      * Made the driver more careful about not leaving bits on
			the screen, or allowing other windows to raise
			themselves: it now re-blanks the screen every so often.
		      * Added `-time' option to `xscreensaver-command'.
		      * Improved SGI screen-grabbing some more: now it can grab
			TrueColor screens into PseudoColor windows and have the
			colors still come out semi-reasonably.
Changes since 1.29:   * Made `slidescreen' and `decayscreen' work better on
			SGIs when windows of different visuals are present, by
			using the XReadDisplay() extension to get a true 24-bit
			image out of the frame buffer.
		      * Made `noseguy' be in color, if compiled with XPM.
		      * Ported `braid', `drift', `fract', `galaxy', `grav',
			`ifs', `julia', `laser', `lightning', `penrose',
			`sierpinski', `slip', `spiral', and `strange' hacks
			from xlockmore.
		      * Merged `hopalong' hack with a more recent version.
		      * Added `cde.txt'.
Changes since 1.27:   * Added `deco', `moire', and `kaleidescope' hacks.
		      * Merged in support for non-Motif locking and demo mode.
		      * Made `blitspin' and `bubbles' work in TrueColor.
		      * Fixed a stupid bug I introduced in `imsmap'.
		      * Added `poly' and `gravity' options to `qix'.
Changes since 1.26:   * Added support for SGI SCREEN_SAVER extension.
		      * Made `fade' and `unfade' work on 8-bit SGIs.
		      * Made the dialog boxes more Motify.
		      * Added `bubbles' hack.
Changes since 1.25:   * Added `lmorph' hack.
		      * Added viscosity and mouse-control to attraction.
		      * Fixed possible bad color choices in qix and attraction.
		      * Added ramp-mode to halo.
		      * Added a new RNG, which is faster and more portable
			than using the RNG in libc.
		      * Made locking work on SCO.
		      * Various other minor tweaks that I don't remember.
Changes since 1.24:   * Made it capture the stdout/stderr of its subprocesses
			and present them on the screensaver window itself.
		      * Made demo mode work correctly with non-default visuals
			and color maps, instead of always using the defaults.
		      * Added -visual argument to all included screenhacks.
		      * Support for the R6 MIT-SCREEN-SAVER server extension.
		      * Made the demo mode list scroll properly.
		      * Added `pedal' hack.
Changes since 1.23:   * Fixed some private-colormap oddities in slidescreen,
			decayscreen, and xroger.  Fixed apparent conservation-
			of-mass problem in pyro; made the shrapnel round.
Changes since 1.22:   * Minor tweaks for IRIX5; fixed locking race condition.
Changes since 1.21:   * Minor tweaks for X11R6.
		      * Fixes for non-default visuals.
Changes since 1.20:   * Fixed bug in color blitspin; added default image.
		      * Added diagnostics to noseguy.  Fixed off-by-one
			error in flame.	 Added some missing casts.
Changes since 1.18:   * Added `flame' hack.
		      * Fixed a minor Motif dialog text field bug.
		      * Fixed yet another XPointer-not-defined-in-R4 bug.
Changes since 1.17:   * Added support for shadow password files.
		      * Fixed some Motif-related locking bugs.
		      * Added diagnostics when locking is disabled.
		      * Made blitspin able to use the XPM library.
		      * Added `decayscreen' hack.
Changes since 1.16:   * Added `halo' hack.
Changes since 1.15:   * Portability fixes.
Changes since 1.14:   * Broke the driver up into more source files.
		      * Moved the hacks into their own directory.
		      * Made all `time' parameters accept the 00:00:00 syntax,
			so that even the parameters which are normally read as
			minutes can be specified in seconds.
		      * Added colormap cycling to `imsmap'.
		      * Made hyper work with K&R compilers.
Changes since 1.13:   * Added `orbit' option to `attraction' hack.
		      * Added `lock-timeout' option.
		      * Cleaned up options of `maze' hack.
Changes since 1.8:    * Added demo mode, and locking.
		      * Added `maze' hack.
		      * Added `norotate' option to `rocks' hack.
