Freeware

Darwersi
Uses an AI that utilizes Darwinian evolution. [Windows]
http://www-sop.inria.fr/cafe/Olivier.Arsac/darwersi/

Edax
Contains everything there is about Edax, one of the strongest Othello programs
http://abulmo.club.fr/edax/index.htm

Edge Reversi
Uses an alpha-beta search with selective extension programmed in Delphi. [Windows]
http://www.stevemaughan.com/reversi.htm

Forest
Contains five levels, game study mode, and other features. [Windows]
http://pagesperso-orange.fr/ocasile/forest.htm

Logistello
Open source program written by Michael Buro, as well as his research papers about related computer science algorithms. [Linux]
http://www.cs.ualberta.ca/~mburo/log.html

NBrowser
A graphical program to read Chris Welty's ntest's opening book
http://othellogateway.com/othello/nbrowser.php

Neurothello
Artificial intelligence othello program, geared toward programmers. [Macintosh]
http://easyweb.easynet.co.uk/~jaffey/neuro.html

Parski's Home Page
Othello game for PalmOS and WinCE devices.
http://www.angelfire.com/ny5/calidadis/cstudio/Parski.htm

Pointy Stone Othello
A strong Othello program that includes internet play between humans and multiple playing brains.
http://www.3dkingdoms.com/pointy3/pointy3main.htm

WZebra
Extremely strong reversi program, with many different levels and an opening book. [Windows 95]
http://www.radagast.se/othello/download.html