GNU Chess - Macintosh Repository

GNU Chess (Mac abandonware from 1995)

Gnu Chess: Most Up-to-Date Encyclopedia, News & Reviews

engines - What free programs do exist to comment chess games? For Windows, Linux, and Mac - Chess Stack Exchange

XBoard - GNU Project - Free Software Foundation

How to install and set up multiple chess engines on XBoard

How to install and set up multiple chess engines on XBoard

GNU Chess

GNU Chess 6.2.8 Is Released - LinuxReviews

Free Open Source Macintosh Chess Software - Chess Forums

90 games from the 80's - Macintosh Repository

ChessX - chess database and FICS client - LinuxLinks