These are the screen savers currently included in the
XScreenSaver distribution.
**Anemotaxis**
**Apollonian**
**Apple2**
**Attraction**
**Barcode**
**BinaryRing**
**Blaster**
**BlinkBox**
**BlitSpin**
**BlockTube**
**Boing**
**Bouboule**
**BoxFit**
**BSOD**
**Bubble3D**
**Cage**
**Carousel**
**CCurve**
**Celtic**
**Cityflow**
**CloudLife**
**CompanionCube**
**Compass**
**Crackberg**
**Crystal**
**Cube21**
**Cubenetic**
**CubeStorm**
**CWaves**
**Cynosure**
**DecayScreen**
**Deco**
**Demon**
**Discrete**
**DymaxionMap**
**Endgame**
**EnergyStream**
**Engine**
**Epicycle**
**Eruption**
**Euler2D**
**Extrusion**
**FadePlot**
**Fireworkx**
**FlipText**
**Flow**
**FluidBalls**
**Flurry**
**FlyingToasters**
**FontGlide**
**Gears**
**Geodesic**
**GeodesicGears**
**GLBlur**
**GLCells**
**GLHanoi**
**GLKnots**
**GLMatrix**
**GLPlanet**
**GLSchool**
**GLSlideshow**
**GLSnake**
**GLText**
**Goop**
**Grav**
**Halftone**
**Hexadrop**
**Hilbert**
**Hopalong**
**Hydrostat**
**Hypertorus**
**Hypnowheel**
**IFS**
**IMSMap**
**Interaggregate**
**Interference**
**Intermomentary**
**JigglyPuff**
**Jigsaw**
**Juggler3D**
**Julia**
**Kaleidescope**
**Kaleidocycle**
**Klein**
**Kumppa**
**Lament**
**Lavalite**
**Lockward**
**Loop**
**m6502**
**Maze**
**MemScroller**
**Menger**
**MetaBalls**
**Möbius**
**MöbiusGears**
**Moiré**
**Moiré2**
**Molecule**
**Munch**
**NoseGuy**
**Pacman**
**Pedal**
**Penetrate**
**Penrose**
**Petri**
**Phosphor**
**Photopile**
**Piecewise**
**Pinion**
**Pipes**
**Polyhedra**
**Polyominoes**
**Polytopes**
**Pong**
**ProjectivePlane**
**Providence**
**Pulsar**
**Pyro**
**Qix**
**QuasiCrystal**
**Queens**
**RaverHoop**
**RDbomb**
**Ripples**
**RomanBoy**
**Rorschach**
**RotZoomer**
**Rubik**
**RubikBlocks**
**ShadeBobs**
**Sierpinski**
**Sierpinski3D**
**SkyTentacles**
**SlideScreen**
**Slip**
**Sonar**
**SpeedMine**
**Spheremonics**
**SplitFlap**
**Spotlight**
**Sproingies**
**Squiral**
**Stairs**
**Starfish**
**StarWars**
**StonerView**
**Strange**
**Substrate**
**Surfaces**
**Tessellimage**
**TimeTunnel**
**Triangle**
**TronBit**
**Unicrud**
**UnknownPleasures**
**VidWhacker**
**Voronoi**
**WebCollage**
**WhirlWindWarp**
**WindupRobot**
**XAnalogTV**
**XFlame**
**XLyap**
**XMatrix**
**XSpirograph**
**Zoom**

There are also some screen savers that were once included, but have since been retired.

Click on the thumbnails for a video preview.

Searches for a source of odor in a turbulent atmosphere. The searcher is able to sense the odor and determine local instantaneous wind direction. The goal is to find the source in the shortest mean time.

Written by Eugene Balkovsky; 2004.

A fractal packing of circles with smaller circles, demonstrating Descartes's theorem.

Wikipedia: "Apollonian gasket"

Wikipedia: "Descartes' theorem"

Written by Allan R. Wilks and David Bagley; 2002.

An Apple ][+ computer simulation, in all its 1979 glory. It also reproduces the appearance of display on a color television set of the period.

In "Basic Programming Mode", a simulated user types in a BASIC program and runs it. In "Text Mode", it displays the output of a program, or the contents of a file or URL. In "Slideshow Mode", it chooses random images and displays them within the limitations of the Apple ][ display hardware. (Six available colors in hi-res mode!)

On MacOS and Linux, this program is also a fully-functional VT100 emulator! Run it as an application instead of as a screen saver and you can use it as a terminal.

Written by Trevor Blackwell and Jamie Zawinski; 2003.

Points attract each other up to a certain distance, and then begin to repel each other. The attraction/repulsion is proportional to the distance between any two particles, similar to the strong and weak nuclear forces.

Written by Jamie Zawinski and John Pezaris; 1992.

Colorful scrolling barcodes. CONSUME!

The barcodes follow the UPC-A, UPC-E, EAN-8 or EAN-13 standards.

Wikipedia: "Universal Product Code"

Wikipedia: "European Article Number"

Written by Dan Bornstein and Jamie Zawinski; 2003.

A system of path tracing particles evolves continuously from an initial creation, alternating dark and light colors.

Written by J. Tarbell and Emilio Del Tessandoro; 2014.

Flying space-combat robots (cleverly disguised as colored circles) do battle in front of a moving star field.

Written by Jonathan Lin; 1999.

A motion-blurred ball bounces inside a box whose tiles only become visible upon impact.

Written by Jeremy English; 2003.

Repeatedly rotates a bitmap by 90 degrees by using logical operations: the bitmap is divided into quadrants, and the quadrants are shifted clockwise. Then the same thing is done again with progressively smaller quadrants, except that all sub-quadrants of a given size are rotated in parallel. As you watch it, the image appears to dissolve into static and then reconstitute itself, but rotated.

Written by Jamie Zawinski; 1992.

A swirling, falling tunnel of reflective slabs. They fade from hue to hue.

Written by Lars R. Damerow; 2003.

A clone of the first graphics demo for the Amiga 1000, which was written by Dale Luck and RJ Mical during a break at the 1984 Consumer Electronics Show (or so the legend goes.)

This looks like the original Amiga demo if you turn off "smoothing" and "lighting" and turn on "scanlines", and is somewhat more modern otherwise.

Wikipedia: "Amiga: Boing Ball"

Written by Jamie Zawinski; 2005.

A deforming balloon with varying-sized spots painted on its invisible surface.

Written by Jeremie Petit; 1997.

Packs the screen with growing squares or circles, colored according to a horizontal or vertical gradient, or according to the colors of a loaded image. The objects grow until they touch, then stop. When the screen is full, they shrink away and the process restarts.

Written by Jamie Zawinski; 2005.

BSOD stands for "Blue Screen of Death". The finest in personal computer emulation, BSOD simulates popular screen savers from a number of less robust operating systems.

Wikipedia: "Blue Screen of Death"

Wikipedia: "Screen of death"

Wikipedia: "Guru Meditation"

Wikipedia: "Row of Bombs"

Wikipedia: "Bomb"

Written by Jamie Zawinski; 1998.

Rising, undulating 3D bubbles, with transparency and specular reflections.

Written by Richard Jones; 1998.

Escher's "Impossible Cage", a 3d analog of a möbius strip, and rotates it in three dimensions.

Wikipedia: "Maurits Cornelis Escher"

Written by Marcelo Vianna; 1998.

Loads several random images, and displays them flying in a circular formation. The formation changes speed and direction randomly, and images periodically drop out to be replaced by new ones.

Written by Jamie Zawinski; 2005.

Generates self-similar linear fractals, including the classic "C Curve".

Written by Rick Campbell; 1999.

Repeatedly draws random Celtic cross-stitch patterns.

Wikipedia: "Celtic knot"

Wikipedia: "Knots and graphs"

Written by Max Froumentin; 2005.

Waves move across a sea of boxes. The city swells. The walls are closing in.

Written by Jamie Zawinski; 2014.

Generates cloud-like formations based on a variant of Conway's Life. The difference is that cells have a maximum age, after which they count as 3 for populating the next generation. This makes long-lived formations explode instead of just sitting there.

Wikipedia: "Conway's Game of Life"

Written by Don Marti; 2003.

The symptoms most commonly produced by Enrichment Center testing are superstition, perceiving inanimate objects as alive, and hallucinations. The Enrichment Center reminds you that the weighted companion cube will never threaten to stab you and, in fact, cannot speak. In the event that the Weighted Companion Cube does speak, the Enrichment Center urges you to disregard its advice.

Written by Jamie Zawinski; 2011.

A compass, with all elements spinning about randomly, for that "lost and nauseous" feeling.

Written by Jamie Zawinski; 1999.

Flies through height maps, optionally animating the creation and destruction of generated tiles; tiles `grow' into place.

Written by Matus Telgarsky; 2005.

Moving polygons, similar to a kaleidoscope. See also the "Kaleidescope" and "GLeidescope" screen savers.

Written by Jouk Jansen; 1998.

The "Cube 21" Rubik-like puzzle, also known as "Square-1". The rotations are chosen randomly. See also the "Rubik", "RubikBlocks" and "GLSnake" screen savers.

Written by Vasek Potocek; 2005.

A cubist Lavalite, sort of. A pulsating set of overlapping boxes with ever-changing blobby patterns undulating across their surfaces.

Written by Jamie Zawinski; 2002.

Boxes change shape and intersect each other, filling space.

Written by Jamie Zawinski; 2003.

A field of sinusoidal colors languidly scrolls. It's relaxing.

Written by Jamie Zawinski; 2007.

Random dropshadowed rectangles pop onto the screen in lockstep.

Written by Ozymandias G. Desiderata, Jamie Zawinski, and Stephen Linhart; 1998.

Melts an image in various ways. Warning, if the effect continues after the screen saver is off, seek medical attention.

Written by David Wald, Vivek Khera, Jamie Zawinski, and Vince Levey; 1993.

Subdivides and colors rectangles randomly, for a Mondrian-esque effect.

Wikipedia: "Piet Mondrian: Paris 1919.

Written by Jamie Zawinski and Michael Bayne; 1997.

A cellular automaton that starts with a random field, and organizes it into stripes and spirals.

Written by David Bagley; 1999.

Discrete map fractal systems, including variants of Hopalong, Julia, and others.

Written by Tim Auckland; 1998.

Buckminster Fuller's map of the Earth projected onto the surface of an unfolded icosahedron. It depicts the Earth's continents as one island, or nearly contiguous land masses.

Wikipedia: "Dymaxion map"

Wikipedia: "Buckminster Fuller"

Written by Jamie Zawinski; 2016.

Black slips out of three mating nets, but the fourth one holds him tight! A brilliant composition!

See also the "Queens" screen saver.

Written by Blair Tennessy and Jamie Zawinski; 2002.

A flow of particles which form an energy stream.

Written by Eugene Sandulenko and Konrad "Yoghurt" Zagorowicz; 2016.

Internal combusion engines.

Wikipedia: "Internal combustion engine: Operation"

Written by Ben Buxton, Ed Beroset and Jamie Zawinski; 2001.

A pre-heliocentric model of planetary motion.

This draws the path traced out by a point on the edge of a circle. That circle rotates around a point on the rim of another circle, and so on, several times.

Wikipedia: "Deferent and epicycle"

Written by James Youngman; 1998.

Exploding fireworks. See also the "Fireworkx", "XFlame" and "Pyro" screen savers.

Written by W.P. van Paassen; 2003.

Simulates two dimensional incompressible inviscid fluid flow.

Wikipedia: "Euler equations"

Wikipedia: "Inviscid flow"

Written by Stephen Montgomery-Smith; 2002.

Various extruded shapes twist and turn inside out.

Written by Linas Vepstas, David Konerding, and Jamie Zawinski; 1999.

A waving ribbon follows a sinusoidal path.

Written by Bas van Gaalen and Charles Vidal; 1997.

Exploding fireworks. See also the "Eruption", "XFlame" and "Pyro" screen savers.

Written by Rony B Chandran; 2004.

Successive pages of text flip in and out in a soothing 3D pattern.

Written by Jamie Zawinski; 2005.

Strange attractors formed of flows in a 3D differential equation phase space. Features the popular attractors described by Lorentz, Roessler, Birkhoff and Duffing, and can discover entirely new attractors by itself.

Wikipedia: "Attractor: Strange attractor"

Written by Tim Auckland; 1998.

Models the physics of bouncing balls, or of particles in a gas or fluid, depending on the settings. If "Shake Box" is selected, then every now and then, the box will be rotated, changing which direction is down (in order to keep the settled balls in motion.)

Written by Peter Birtles and Jamie Zawinski; 2002.

A colourful star(fish)like flurry of particles.

Original Mac version: http://

Written by Calum Robinson and Tobias Sargeant; 2002.

A fleet of 3d space-age jet-powered flying toasters (and toast!) Inspired by the ancient Berkeley Systems After Dark flying toasters.

Wikipedia: "After Dark (software): Flying Toasters"

Written by Jamie Zawinski and Devon Dossett; 2003.

Puts text on the screen using large characters that glide in from the edges, assemble, then disperse. Alternately, it can simply scroll whole sentences from right to left.

Written by Jamie Zawinski; 2003.

Interlocking gears. See also the "Pinion" and "MöbiusGears" screen savers.

Wikipedia: "Involute gear"

Wikipedia: "Epicyclic gearing"

Written by Jamie Zawinski; 2007.

A mesh geodesic sphere of increasing and decreasing complexity.

A geodesic sphere is an icosohedron whose equilateral faces are sub-divided into non-equilateral triangles to more closely approximate a sphere.

The animation shows the equilateral triangles subdivided into four coplanar equilateral triangles; and then inflated outward, causing the sub-triangles to no longer be equilateral, but to more closely approximate the surface of a sphere.

Wikipedia: "Geodesic dome"

Wikipedia: "Buckminster Fuller"

Written by Jamie Zawinski; 2013.

A set of meshed gears arranged on the surface of a sphere.

Wikipedia: "Geodesic dome"

Wikipedia: "Involute gear"

Wikipedia: "Buckminster Fuller"

Written by Jamie Zawinski; 2014.

Flowing field effects from the vapor trails around a moving object.

This is done by rendering the scene into a small texture, then repeatedly rendering increasingly-enlarged and increasingly-transparent versions of that texture onto the frame buffer. As such, it's quite GPU-intensive: if you don't have a very good graphics card, it will hurt your machine bad.

Written by Jamie Zawinski; 2002.

Cells growing, dividing and dying on your screen. Microscopic pathos.

Written by Matthias Toussaint; 2007.

Solves the Towers of Hanoi puzzle. Move N disks from one pole to another, one disk at a time, with no disk ever resting on a disk smaller than itself.

Written by Dave Atkinson; 2005.

Generates some twisting 3d knot patterns. Spins 'em around.

Written by Jamie Zawinski; 2003.

The 3D "digital rain" effect, as seen in the title sequence of "The Matrix".

See also "xmatrix" for a 2D rendering of the similar effect that appeared on the computer monitors actually *in* the movie.

Wikipedia: "Matrix digital rain"

Written by Jamie Zawinski; 2003.

The Earth, bouncing around in space.

If you would like it to display a different planet, the texture maps that come with "ssystem" work well.

Written by David Konerding and Jamie Zawinski; 1998.

A school of fish, using the classic "Boids" algorithm by Craig Reynolds.

Written by David C. Lambert and Jamie Zawinski; 2006.

Loads a random sequence of images and smoothly scans and zooms around in each, fading from pan to pan.

Written by Jamie Zawinski and Mike Oliphant; 2003.

The "Rubik's Snake" puzzle. See also the "Rubik" and "Cube21" screen savers.

Written by Jamie Wilkinson, Andrew Bennetts, and Peter Aylett; 2002.

Displays a few lines of text spinning around in a solid 3D font. The text can use strftime() escape codes to display the current date and time.

Written by Jamie Zawinski; 2001.

Amoeba-like blobs change shape as they wander around the screen. They are translucent, so you can see the lower blobs through the higher ones, and when one passes over another, their colors merge. I got the idea for this from a mouse pad I had once, which achieved the same kind of effect in real life by having several layers of plastic with colored oil between them.

Written by Jamie Zawinski; 1997.

An orbital simulation. With trails enabled, it looks kind of like a cloud-chamber photograph.

Written by Greg Bowering; 1997.

A halftone dot pattern in motion.

Draws the gravity force in each point on the screen seen through a halftone dot pattern. The gravity force is calculated from a set of moving mass points. View it from a distance for best effect.

Written by Peter Jaric; 2002.

A grid of hexagons or other shapes, with tiles dropping out.

Wikipedia: "Tiling by regular polygons"

Written by Jamie Zawinski; 2013.

The recursive Hilbert space-filling curve, both 2D and 3D variants. It incrementally animates the growth and recursion to the maximum depth, then unwinds it back.

The Hilbert path is a single contiguous line that can fill a volume without crossing itself. As a data structure, Hilbert paths are useful because ordering along the curve preserves locality: points that are close together along the curve are also close together in space. The converse is often, but not always, true. The coloration reflects this.

Written by Jamie Zawinski; 2011.

Lacy fractal patterns based on iteration in the imaginary plane, from a 1986 Scientific American article. See also the "Discrete" screen saver.

Written by Patrick Naughton; 1992.

Wiggly squid or jellyfish with many tentacles.

A muscular hydrostat is a biological structure used to move its host about, consisting of muscles with no skeletal support. It performs its hydraulic movement without fluid in a separate compartment, as in a hydrostatic skeleton.

Wikipedia: "Muscular hydrostat"

Written by Justin Windle and Jamie Zawinski; 2016.

A Clifford Torus: a torus lying on the "surface" of a 4D hypersphere. Inspired by Thomas Banchoff's book "Beyond the Third Dimension: Geometry, Computer Graphics, and Higher Dimensions", Scientific American Library, 1990.

Wikipedia: "N-sphere"

Wikipedia: "Clifford torus"

Wikipedia: "Regular polytope"

Written by Carsten Steger; 2003.

A overlapping, translucent spiral patterns. The tightness of their spirals fluctuates in and out.

Written by Jamie Zawinski; 2008.

Clouds of iterated function systems spin and collide.

Note that the "Detail" parameter is exponential. Number of points drawn is functions^detail.

Wikipedia: "Iterated function system"

Written by Chris Le Sueur and Robby Griffin; 1997.

Cloud-like patterns. The idea is to take four points on the edge of the image, and assign each a random "elevation". Then find the point between them, and give it a value which is the average of the other four, plus some small random offset. Coloration is done based on elevation.

Written by Juergen Nickelsen and Jamie Zawinski; 1992.

Pale pencil-like scribbles slowly fill the screen.

A surface is filled with a hundred medium to small sized circles. Each circle has a different size and direction, but moves at the same slow rate. Displays the instantaneous intersections of the circles as well as the aggregate intersections of the circles.

Though actually it doesn't look like circles at all!

Written by Casey Reas, William Ngan, Robert Hodgin, and Jamie Zawinski; 2004.

Color field based on computing decaying sinusoidal waves.

Written by Hannu Mallat; 1998.

Blinking dots interact with each other circularly.

A surface is filled with a hundred medium to small sized circles. Each circle has a different size and direction, but moves at the same slow rate. Displays the instantaneous intersections of the circles as well as the aggregate intersections of the circles.

The circles begin with a radius of 1 pixel and slowly increase to some arbitrary size. Circles are drawn with small moving points along the perimeter. The intersections are rendered as glowing orbs. Glowing orbs are rendered only when a perimeter point moves past the intersection point.

Written by Casey Reas, William Ngan, Robert Hodgin, and Jamie Zawinski; 2004.

Quasi-spherical objects are distorted.

You have a tetrahedron with tesselated faces. The vertices on these faces have forces on them: one proportional to the distance from the surface of a sphere; and one proportional to the distance from the neighbors. They also have inertia. The resulting effect can range from a shape that does nothing, to a frenetic polygon storm. Somewhere in between there it usually manifests as a blob that jiggles in a kind of disturbing manner.

Written by Keith Macleod; 2003.

Carves an image up into a jigsaw puzzle, shuffles it, and solves it.

Wikipedia: "Jigsaw puzzle"

Wikipedia: "Tessellation"

Written by Jamie Zawinski; 1997.

A 3D juggling stick-man, with Cambridge juggling pattern notation used to describe the patterns he juggles.

Written by Tim Auckland and Jamie Zawinski; 2002.

The Julia set is a close relative of the Mandelbrot set. The small moving dot indicates the control point from which the rest of the image was generated. See also the "Discrete" screen saver.

Written by Sean McCullough; 1997.

A simple kaleidoscope made of line segments. See "GLeidescope" for a more sophisticated take.

Written by Ron Tapia; 1997.

Draw a ring composed of tetrahedra connected at the edges that twists and rotates toroidally.

When a series of tetrahedra are joined at the edges in a loop, it is possible for them to rotate continously through the center without deforming. This only works with an even number of tetrahedra, and there must be eight or more, or they don't fit.

Written by Jamie Zawinski; 2013.

A Klein bottle is the 4D analog of a möbius strip.

You can walk on the surface of the bottle or rotate it in 4D or walk on it while it rotates in 4D. Inspired by Thomas Banchoff's book "Beyond the Third Dimension: Geometry, Computer Graphics, and Higher Dimensions", Scientific American Library, 1990.

Written by Carsten Steger; 2008.

Spiraling, spinning, and very, very fast splashes of color rush toward the screen.

Written by Teemu Suutari; 1998.

Lemarchand's Box, the Lament Configuration.

Warning: occasionally opens doors.

Written by Jamie Zawinski; 1998.

A Simulation a Lava Lite(r). Odd-shaped blobs of a mysterious substance are heated, slowly rise to the top of the bottle, and then drop back down as they cool. This simulation requires a fairly fast machine (both CPU and 3D performance.)

"LAVA LITE(r) and the configuration of the LAVA(r) brand motion lamp are registered trademarks of Haggerty Enterprises, Inc. The configuration of the globe and base of the motion lamp are registered trademarks of Haggerty Enterprises, Inc. in the U.S.A. and in other countries around the world."

Wikipedia: "Lava lamp"

Wikipedia: "Metaballs"

Wikipedia: "Lavarand"

Written by Jamie Zawinski; 2002.

A translucent spinning, blinking thing. Sort of a cross between the wards in an old combination lock and those old backlit information displays that animated and changed color via polarized light.

Written by Leo L. Schwab; 2007.

A cellular automaton that generates loop-shaped colonies that spawn, age, and eventually die.

Written by David Bagley; 1999.

Emulates a 6502 microprocessor, and runs some example programs on it.

The family of 6502 chips were used throughout the 70's and 80's in machines such as the Atari 2600, Commodore PET, VIC20 and C64, Apple ][, and the NES. Some example programs are included, and it can also read in an assembly file as input.

Original JavaScript Version by Stian Soreng: http://

Written by Stian Soreng and Jeremy English; 2007.

Generates random mazes, with three different algorithms: Kruskal, Prim, and a depth-first recursive backtracker. It also solves them. Backtracking and look-ahead paths are displayed in different colors.

Wikipedia: "Maze generation algorithm"

Wikipedia: "Maze solving algorithm"

Written by Martin Weiss, Dave Lemke, Jim Randell, Jamie Zawinski, Johannes Keukelaar, and Zack Weinberg; 1985.

Scrolls a dump of its own memory in three windows at three different rates.

Written by Jamie Zawinski; 2004.

The Menger Gasket is a cube-based recursive fractal object analagous to the Sierpinski Tetrahedron.

Wikipedia: "Menger sponge"

Wikipedia: "Sierpinski carpet"

Written by Jamie Zawinski; 2001.

2D meta-balls: overlapping and merging balls with fuzzy edges.

Written by W.P. van Paassen; 2003.

M. C. Escher's "Möbius Strip II", an image of ants walking along the surface of a möbius strip.

Wikipedia: "Möbius strip"

Wikipedia: "Maurits Cornelis Escher"

Written by Marcelo F. Vianna; 1997.

An interlinked loop of rotating gears. The layout of the gears follows the path of a möbius strip. See also the "Pinion" and "Gears" screen savers.

Wikipedia: "Involute gear"

Wikipedia: "Möbius strip"

Written by Jamie Zawinski; 2007.

When the lines on the screen

Make more lines in between,

That's a moiré!

Written by Jamie Zawinski and Michael Bayne; 1997.

Generates fields of concentric circles or ovals, and combines the planes with various operations. The planes are moving independently of one another, causing the interference lines to spray.

Written by Jamie Zawinski; 1998.

Some interesting molecules. Several molecules are built in, and it can also read PDB (Protein Data Bank) files as input.

Wikipedia: "Protein Data Bank"

Written by Jamie Zawinski; 2001.

DATAI 2

ADDB 1,2

ROTC 2,-22

XOR 1,2

JRST .-4

As reported by HAKMEM (MIT AI Memo 239, 1972), Jackson Wright wrote the above PDP-1 code in 1962. That code still lives on here, some 46 years later.

In "mismunch" mode, it displays a creatively broken misimplementation of the classic munching squares algorithm instead.

Wikipedia: "HAKMEM"

Wikipedia: "Munching square"

Written by Jackson Wright, Tim Showalter, Jamie Zawinski and Steven Hazel; 1997.

A little man with a big nose wanders around your screen saying things.

Written by Dan Heller and Jamie Zawinski; 1992.

Simulates a game of Pac-Man on a randomly-created level.

Written by Edwin de Jong and Jamie Zawinski; 2004.

The even-odd winding rule.

Wikipedia: "Even-odd rule"

Wikipedia: "Nonzero-rule"

Written by Dale Moore; 1995.

Simulates (something like) the classic arcade game Missile Command.

Written by Adam Miller; 1999.

Quasiperiodic tilings.

In April 1997, Sir Roger Penrose, a British math professor who has worked with Stephen Hawking on such topics as relativity, black holes, and whether time has a beginning, filed a copyright-infringement lawsuit against the Kimberly-Clark Corporation, which Penrose said copied a pattern he created (a pattern demonstrating that "a nonrepeating pattern could exist in nature") for its Kleenex quilted toilet paper. Penrose said he doesn't like litigation but, "When it comes to the population of Great Britain being invited by a multinational to wipe their bottoms on what appears to be the work of a Knight of the Realm, then a last stand must be taken."

As reported by News of the Weird #491, 4-Jul-1997.

Wikipedia: "Penrose tiling"

Wikipedia: "Tessellation"

Written by Timo Korvola; 1997.

Colonies of mold grow in a petri dish. Growing colored circles overlap and leave spiral interference in their wake.

Written by Dan Bornstein; 1999.

An old terminal with large pixels and long-sustain phosphor.

On MacOS and Linux, this program is also a fully-functional VT100 emulator! Run it as an application instead of as a screen saver and you can use it as a terminal.

Written by Jamie Zawinski; 1999.

Loads several random images, and displays them as if lying in a random pile. The pile is periodically reshuffled, with new images coming in and old ones being thrown out.

Written by Jens Kilian and Jamie Zawinski; 2008.

Moving circles switch from visibility to invisibility at intersection points.

Written by Geoffrey Irving; 2003.

A gear system marches across the screen. See also the "Gears" and "MöbiusGears" screen savers.

Written by Jamie Zawinski; 2004.

A growing plumbing system, with bolts and valves.

Written by Marcelo Vianna and Jamie Zawinski; 1997.

The 75 uniform polyhedra and their duals, plus 5 prisms and antiprisms, and some information about each.

Wikipedia: "Uniform polyhedra"

Wikipedia: "Stellation"

Wikipedia: "Dual polyhedron"

Wikipedia: "Antiprism"

Written by Dr. Zvi Har'El and Jamie Zawinski; 2004.

Repeatedly attempts to completely fill a rectangle with irregularly-shaped puzzle pieces.

Written by Stephen Montgomery-Smith; 2002.

The six regular 4D polytopes rotating in 4D.

Inspired by H.S.M Coxeter's book "Regular Polytopes", 3rd Edition, Dover Publications, Inc., 1973, and Thomas Banchoff's book "Beyond the Third Dimension: Geometry, Computer Graphics, and Higher Dimensions", Scientific American Library, 1990.

Wikipedia: "Hypercube"

Wikipedia: "Tesseract"

Wikipedia: "Regular polytope"

Written by Carsten Steger; 2003.

The 1971 Pong home video game, including artifacts of an old color TV set.

In clock mode, the score keeps track of the current time.

Written by Jeremy English, Trevor Blackwell and Jamie Zawinski; 2003.

A 4D embedding of the real projective plane.

You can walk on the surface of the real projective plane or rotate it in 4D or walk on it while it rotates in 4D. Inspired by Thomas Banchoff's book "Beyond the Third Dimension: Geometry, Computer Graphics, and Higher Dimensions", Scientific American Library, 1990.

Wikipedia: "Real projective plane"

Wikipedia: "Roman surface"

Wikipedia: "Cross cap"

Wikipedia: "Möbius strip"

MathWorld: "Real Projective Plane"

MathWorld: "Roman Surface"

MathWorld: "Cross-Cap"

MathWorld: "Möbius Strip"

Written by Carsten Steger; 2014.

"A pyramid unfinished. In the zenith an eye in a triangle, surrounded by a glory, proper."

Wikipedia: "Eye of Providence"

Written by Blair Tennessy; 2004.

Intersecting planes, with alpha blending, fog, textures, and mipmaps.

Written by David Konerding; 1999.

Exploding fireworks. See also the "Fireworkx", "Eruption", and "XFlame" screen savers.

Written by Jamie Zawinski; 1992.

Bounces a series of line segments around the screen, and uses variations on this basic motion pattern to produce all sorts of different presentations: line segments, filled polygons, and overlapping translucent areas.

Written by Jamie Zawinski; 1992.

A quasicrystal is a structure that is ordered but aperiodic. Two-dimensional quasicrystals can be generated by adding a set of planes where x is the sine of y. Different complex aperiodic plane tilings are produced depending on the period, position, and rotation of the component planes, and whether the rotation of the planes is evenly distributed around the circle (the "symmetry" option, above) or random.

See also the "RD-Bomb", "CWaves" and "Penrose" screen savers.

Written by Jamie Zawinski; 2013.

The N-Queens problem: how to place N queens on an NxN chessboard such that no queen can attack a sister?

See also the "Endgame" screen saver.

Wikipedia: "Eight queens puzzle"

Written by Blair Tennessy and Jamie Zawinski; 2002.

Simulates an LED hula hoop in a dark room. Oontz oontz oontz.

Written by Jamie Zawinski; 2016.

Reaction-diffusion: draws a grid of growing square-like shapes that, once they overtake each other, react in unpredictable ways.

Written by Scott Draves; 1997.

Rippling interference patterns reminiscent of splashing water distort a loaded image.

Written by Tom Hammersley; 1999.

A 3D immersion of the real projective plane that smoothly deforms between the Roman surface and the Boy surface.

You can walk on the surface of the real projective plane or rotate it in 3D. Furthermore, it is possible to smoothly deform the real projective plane between the Roman surface and the Boy surface while turning it or walking on it. Inspired by François Apéry's book "Models of the Real Projective Plane", Vieweg, 1987.

Wikipedia: "Boy's surface"

Wikipedia: "Roman surface"

MathWorld: "Boy Surface"

MathWorld: "Roman Surface"

Written by Carsten Steger; 2014.

Inkblot patterns via a reflected random walk.

Wikipedia: "Rorschach inkblot test"

Wikipedia: "Random walk"

Written by Jamie Zawinski; 1992.

Distorts an image by rotating and scaling random sections of it.

Written by Claudio Matsuoka; 2001.

A Rubik's Cube that repeatedly shuffles and solves itself. See also the "GLSnake" and "Cube21" screen savers.

Written by Marcelo Vianna; 1997.

The "Rubik's Mirror Blocks" puzzle. See also the "Rubik", "Cube21", and "GLSnake" screen savers.

Wikipedia: "Combination puzzles: Irregular cuboids"

Written by Vasek Potocek; 2009.

Oscillating oval patterns that look something like vapor trails or neon tubes.

Written by Shane Smit; 1999.

The 2D Sierpinski triangle fractal. See also the "Sierpinski3D" screen saver.

Wikipedia: "Sierpinski triangle"

Written by Desmond Daignault; 1997.

The recursive Sierpinski tetrahedron fractal.

Wikipedia: "Sierpinski triangle: Analogs in higher dimension"

Written by Jamie Zawinski and Tim Robinson; 1999.

There is a tentacled abomination in the sky. From above you it devours.

Written by Jamie Zawinski; 2008.

A variant on a "fifteen puzzle", operating on the screen or an image. It divides the image into a grid and randomly shuffles the squares.

Written by Jamie Zawinski; 1994.

A jet engine consumes the screen, then puts it through a spin cycle.

Written by Scott Draves and Jamie Zawinski; 1997.

A sonar display pings (get it?) the hosts on your local network, and plots their distance (response time) from you. The three rings represent ping times of approximately 2.5, 70 and 2,000 milliseconds respectively.

Alternately, it can run a simulation that doesn't involve hosts.

Written by Jamie Zawinski and Stephen Martin; 1998.

Simulates speeding down a rocky mineshaft, or a funky dancing worm.

Written by Conrad Parker; 2001.

These closed objects are commonly called spherical harmonics, although they are only remotely related to the mathematical definition found in the solution to certain wave functions, most notably the eigenfunctions of angular momentum operators.

Wikipedia: "Spherical harmonics: Visualization of the spherical harmonics"

Written by Paul Bourke and Jamie Zawinski; 2002.

Simulates a split-flap display, an old style of electromechanical sign as seen in airports and train stations, and commonly used in alarm clocks in the 1960s and 1970s.

Wikipedia: "Split-flap display"

Wikipedia: "Flip clock"

Written by Jamie Zawinski; 2015.

A spotlight scanning across a black screen, illuminating a loaded image when it passes.

Written by Rick Schultz and Jamie Zawinski; 1999.

Slinky-like creatures walk down an infinite staircase and occasionally explode!

Wikipedia: "Slinky"

Wikipedia: "Q*bert"

Wikipedia: "Marble Madness"

Written by Ed Mackey; 1997.

Square-spiral-producing automata. The spirals grow outward until they hit something, then they go around it.

Written by Jeff Epler; 1999.

Escher's infinite staircase.

Wikipedia: "Maurits Cornelis Escher"

Written by Marcelo Vianna and Jamie Zawinski; 1998.

Undulating, throbbing, star-like patterns pulsate, rotate, and turn inside out. Another display mode uses these shapes to lay down a field of colors, which are then cycled. The motion is very organic.

Written by Jamie Zawinski; 1997.

A stream of text slowly scrolling into the distance at an angle, over a star field, like at the beginning of the movie of the same name.

Wikipedia: "Star Wars opening crawl"

Written by Jamie Zawinski and Claudio Matauoka; 2001.

Chains of colorful squares dance around each other in complex spiral patterns. Inspired by David Tristram's `electropaint' screen saver, originally written for SGI computers in the late 1980s or early 1990s.

Written by Andrew Plotkin; 2001.

Strange attractors: a swarm of dots swoops and twists around.

Wikipedia: "Attractor: Strange attractor"

Written by Massimino Pascal; 1997.

Crystalline lines grow on a computational substrate. A simple perpendicular growth rule creates intricate city-like structures.

Written by J. Tarbell and Mike Kershaw; 2004.

Parametric surfaces.

MathWorld: "Dinis Surface"

Wikipedia: "Enneper surface"

MathWorld: "Ennepers Minimal Surface"

MathWorld: "Kuen Surface"

Wikipedia: "Möbius strip"

MathWorld: "Seashell"

MathWorld: "Swallowtail Catastrophe"

MathWorld: "Bohemian Dome"

Wikipedia: "Whitney umbrella"

MathWorld: "Plueckers Conoid"

MathWorld: "Hennebergs Minimal Surface"

MathWorld: "Catalans Surface"

MathWorld: "Corkscrew Surface"

Written by Andrey Mirtchovski and Carsten Steger; 2003.

Converts an image to triangles using Delaunay tessellation, and animates the result at various depths.

More triangles are allocated to visually complex parts of the image. This is accomplished by first computing the first derivative of the image: the distance between each pixel and its neighbors (which is essentially edge detection or embossing). Then the Delaunay control points are chosen by selecting those pixels whose distance value is above a certain threshold: those are the pixels that have the largest change in color/brightness.

Wikipedia: "Delaunay triangulation"

Written by Jamie Zawinski; 2014.

An animation similar to the opening and closing effects on the Dr. Who TV show.

Written by Sean P. Brennan; 2005.

Generates random mountain ranges using iterative subdivision of triangles.

Written by Tobias Gloth; 1997.

The character "Bit" from the film, "Tron".

The "yes" state is a tetrahedron; the "no" state is the second stellation of an icosahedron; and the idle state oscillates between a small triambic icosahedron and the compound of an icosahedron and a dodecahedron.

Wikipedia: "List of Tron characters: Bit"

Wikipedia: "Uniform polyhedra"

Wikipedia: "Stellation"

Written by Jamie Zawinski; 2011.

Chooses a random Unicode character and displays it full screen, along with some information about it.

Written by Jamie Zawinski; 2016.

PSR B1919+21 (AKA CP 1919) was the first pulsar ever discovered: a spinning neutron star emitting a periodic lighthouse-like beacon. An illustration of the signal received from it was published in Scientific American in 1971, and later in The Cambridge Encyclopedia of Astronomy in 1977, where it was seen by Stephen Morris, the drummer of Joy Division, and was consequently appropriated by Peter Saville for the cover of the band's album "Unknown Pleasures".

Wikipedia: "Pulsar"

Wikipedia: "PSR B1919+21"

Wikipedia: "Unknown Pleasures"

Wikipedia: "Peter Saville"

Wikipedia: "Joy Division"

Written by Jamie Zawinski; 2013.

Displays a distorted frame video.

This is a shell script that grabs a frame of video from the system's video input, and then uses some PBM filters (chosen at random) to manipulate and recombine the video frame in various ways (edge detection, subtracting the image from a rotated version of itself, etc.) Then it displays that image for a few seconds, and does it again. This works really well if you just feed broadcast television into it.

Written by Jamie Zawinski; 1998.

A Voronoi tessellation. Periodically zooms in and adds new points. The existing points also wander around.

There are a set of control points on the plane, each at the center of a colored cell. Every pixel within that cell is closer to that cell's control point than to any other control point. That is what determines the cell's shapes.

Wikipedia: "Voronoi diagram"

Wikipedia: "Tessellation"

Written by Jamie Zawinski; 2007.

This is what the Internet looks like.

This creates collages out of random images from the World Wide Web. It finds the images by feeding random words into various search engines, and pulling images (or sections of images) out of the pages returned.

WARNING: THE INTERNET SOMETIMES CONTAINS PORNOGRAPHY.

The Internet being what it is, absolutely anything might show up in the collage including -- quite possibly -- pornography, or even nudity. Please act accordingly.

See also https://

Written by Jamie Zawinski; 1999.

Floating stars are acted upon by a mixture of simple 2D force fields. The strength of each force field changes continuously, and it is also switched on and off at random.

Written by Paul 'Joey' Clark; 2001.

A swarm of wind-up toy robots wander around the table-top, bumping into each other. Each robot contains a mechanically accurate gear system inside, which you can see when the robot's shell occasionally fades to transparency. Also, sometimes a cartoony word bubble pops up above a robot, full of random text.

Written by Jamie Zawinski; 2014.

An old TV set, including artifacts like snow, bloom, distortion, ghosting, and hash noise. It also simulates the TV warming up. It will cycle through 12 channels, some with images you give it, and some with color bars or nothing but static.

Written by Trevor Blackwell; 2003.

Pulsing fire. It can also take an arbitrary image and set it on fire too.

Written by Carsten Haitzler and many others; 1999.

The Lyapunov exponent makes pretty fractal pictures.

Wikipedia: "Lyapunov exponent"

Written by Ron Record; 1997.

The "digital rain" effect, as seen on the computer monitors in "The Matrix".

See also "GLMatrix" for a 3D rendering of the similar effect that appeared in the movie's title sequence.

Wikipedia: "Matrix digital rain"

Written by Jamie Zawinski; 1999.

Simulates that pen-in-nested-plastic-gears toy from your childhood.

Written by Rohit Singh; 2000.

Fatbits! Zooms in on a part of the screen and then moves around. With the "Lenses" option, the result is like looking through many overlapping lenses rather than just a simple zoom.

Written by James Macnicol; 2001.

There are also some screen savers that were once included, but have since been retired.