ButtonMaker Duo by Roberto Puon: Platform: Windows and Mac. Photoshop and PSP compatible: Transforms either a rectangular or circular selection into 3D buttons with beveled edges and highlights through the use of a simple slider based interface. 

Cybia: Creative Resource Studio (7 collections of Filters for Photoshop and PSP compatible programs) Platform: Windows and Mac. Filters include: Alpha, Color, Edge, Screen Works: 20 plug-in filters that produce various screen/mesh overlay effects. Emboss Works: 20 plug-in filters that produce various embossing effects Swap, Blaster

DC Special 2.0 Plugin Filters for Photoshop / PSP
3 collections with various effects. 

Fantastic Machines (Tile Tools / Paint Engine - Photoshop and PSP) 

Filter Factory Collection A - V as well as Andrew Buckle filters 1-62

Free [email protected]
Eliminate White Filter: Generates transparency in a layer based on the "whiteness" of each pixel color. Platform: Mac and Windows95. Grid Creator Filter (Mac only) Creates grid pattern. You can control, horizontal and vertical grids' interval, width, offset and opacity. Grid pattern will be made of a color (out of 64 pre-selected colors) or existing image on the target layer.

Greg's Factory Output Vol I,II Available in WIndows and Mac
Various effects

Harry the Raver Platform: Windows and Macintosh. VideoRave: 32 filters most of which produce different colored effects on an image. Cryptology: 7 filters which allow one to encrypt and decrypt picture and video files. Nirvana: 4 filters which generate colored patterns

Johann's Filters   PC Photoshop or any compatible program (PSP)
Symmetric Pattern1, Symmetric Pattern2, Symmetric Pattern3 (Sine based pattern generators) Focal Blur: Blurs the image outside of a circular region and turns it to grayscale. Blurred Mesh: Draws a black, blurred mesh over the current image. Platform: 32bit, Windows 95, Windows NT 4.0

Kang's Filters (PC and Mac)

Krusty's FX Filters (Photoshop and PSP)
Krusty's FX 1.0.1 vol. I,II & III

Neology / Filter Factory Homepage by Werner D. Streidt (freeware)
Platform: PC and Mac. 23 filters with various effects.

NVR Border Mania Plugins for Photoshop, PSP and Corel Photo-Paint
Create a variety of basic borders around images and are particularly well suited to creating buttons for Web pages. English and French Versions available. Distributed as freeware/shareware combination. 

MA & D Plugins (Otherwise known as Mock Filters) Includes 3 filters: LaserSight, Bevel, Mosaic. Platform: WIndows / Mac. This site also offers a few original brushes and actions for Photoshop.

Mark's Filters Page Curl: creates a curl effect on the edge of a picture.
Remove white: Will make white pixels transparent, and partially white pixels partially transparent. Page curl II: Improved version of his initial page curl

Media Spark (Image Editing Filters) Set of 9 filters. Distributed as freeware.
Work on: Adobe Photoshop, Fractal Design Painter, Macromedia Director and PSP. Effects: Darken Edges, Darken RGB Edges, Pixelate Edges Black, Black Vignette Transparent, Vignette White, Pixelaters, White Out, Examples of what the filters do can be seen on their site.

Plugin Com HQ / Plugins and Tools Plugin Commander (Pico)

Redfield Plug-ins  Commercial and freeware plug-ins available
(Jama 3D plug-in) creates corrugated and cellular like patterns from 2D image. Redfield Mesh 3D: (Freeware) PC / Photoshop and PSP compatible. Nettings effect designer Redfield Jama 2000 (commercial version of Jama 3D)

Simple Filters / Photoshop - PSP  compatible (Sandy Blair) Simple Filters contains 10 filters with no adjustable settings. Filters include: Offset 3, Half Wrap, Top Left Mirror, Center Tile, Zoom Out and Flip, Blintz Tile, Diamond, Horizontal grain, Pizza Slice Mirror, Four Way Average
Nue Filters (Sandy Blair) 10 filters that generate various patterns. 
Ecosse set of 3 filters, False color, Flutter and metal Emboss.

Toad's Slimy Mudhole IIya Razmonov aka Illyich the Toad
(Toadies filters (freeware) 

True Filters for Photoshop by Truman Brown (Commercial with one filter offered for free) 10 commercial filters which include: Horizontal Mirror, Vertical Mirror, Diagonal Mirror, Inversion Mirror, Polar Pinwheel, Horizontal, Crossfade, Vertical Crossfade, QuickTile One, QuickTile Two, Quick Bevel. Also offered on Truman's site is Beveled Edge-blender: (freeware) This filter enables you to convert almost any image into a virtually seamless tile using an edge blending algorithm. 

Unlead Web Utilities (Art Texture Plug-in Free)

VanDerLee Unplugged Filters (Download Page for PC and Mac - Freeware) 4 sets of filters. Colors, Effects, Shapes, Tools, Colors:(Color based effects. Brightness, inversion, contrast, etc) Effects: (Noise, television effects, dithering, and pencil retracing etc) Shapes: (Creates various shapes on your image) Tools:( Bend, rotate, twist, radar screens, waves, lighting effects, etc)

Commercial or Shareware Demos

Axion Software: Several commercial filters which produce lens Flares and sparkle effects . Several older versions of their commercial counterparts are offered for free and and may be downloaded from their site. Axion Lens Flare 16bit, Axion Glow 16bit, Axion Lens Flare32 and Glow32 Photoshop filters 

Flaming Pear Blade Pro Two week trial available. A few freeware filters are also available on the Freebies page: ChromaSolarize, Tachyon, Ghost, Make Opaque, Vitriol, ColorSwap (WIndows/Mac) / In addition there are 6 texture collections also available for free download.

Alien Skin Software: (Eye Candy / Xenofex Demos Available)
Eye Candy 4000 Beta version is available ( Will expire on Oct 31, 2000)
Xenofex: Contains 16 plugins with various effects. 2 of the 16 plugins (Crumple & Stain) work in the demo version. 

Plugin Galaxy Effects: Set of 20 filters Windows demo version, and Macintosh trial version availalbe. Various effects.

Xaos Tools: Demo Available. WIndows and Mac This package includes, Paint Alchemy, Terrazzo and Type Caster. Save feature is disabled in the demo.