Crack Attack
- OpenGL Linux version of Tetris Attack in which you can eliminate blocks horizontally or vertically. (Open Source, GPL)
- http://aluminumangel.org/attack/

Stacker Blocks 3D
- A falling blocks game for Windows in the style of classic Tetris. However, unlike classic Tetris, Stacker Blocks uses Direct3D graphics to give the game added visual appeal. (Open Source, GPL)
- http://stacker-blocks.sourceforge.net/

Wiz Tris
- Columns-style game with customizable graphics and sound, for Windows.
- http://tellini.info/software/wiztris/

Tetris
- Windows version with sound, and the ability to minimize to the system tray.
- http://www.crystaloffice.com/tetrinfo.html

Super ACiD Block Attack
- Use falling blocks to fill in up to five horizontal rows. With music. For DOS or Windows.
- http://dddgames.com/saba/

BedTer
- Tetris clone with customizable graphics and sound. Available for Windows 9x/NT (requires DirectX) or Linux.
- http://www.abednarz.net/bedter.html

GLBlocks
- Multicolor square blocks are falling; lines disappear when four segments of the same color touch. For Windows, and a port to Game Park's GP32 handheld gaming console.
- http://www.lysator.liu.se/~sdw/glblocks.html

StefTris
- Windows Tetris for two players.
- http://steftris.hit.bg/

LTris
- A Tetris clone for Linux.
- http://lgames.sourceforge.net/index.php?project=LTris

Bricks2000
- Tetris clone for Windows.
- http://doob.info/Bricks2000/

Tetron
- Multiplayer Tetris for Windows for up to eight players. Features internet play, customizable skins and sound themes.
- http://www.tetron2000.com/

U61
- Multiplayer network falling block based game for Windows or Linux. (Open Source, GPL)
- http://www.ufoot.org/u61/

Tetanus On Drugs
- Simulates a game of Tetris under the influence of hallucinogens for DOS, Linux, or Windows. (Open source, GPL)
- http://pineight.8m.com/tod.htm

Horses Tetris
- A Tetris clone for Windows with pictures of horses in the background. Other clones available, including some with holiday themes.
- http://www.tnpsc.com/ssaver/horses.htm

Eittris
- Tetris knockoff for Windows offering multi-person competitive play with up to four players and high scores on the web.
- http://www.ericjorgensen.com/eittris/

Quadra
- Multiplayer internet Tetris for Linux or Windows.
- http://quadra.sourceforge.net/