3 links
ATPM Chess Roundup
atpm.com
Review/ratings of 5 free Macintosh chess programs: Sigma Chess(Excellent), MacChess (Very Nice), ChessWorks (Good), GNUChess (Okay), Vampire Chess (Rotten)
ATPM: Mac Chess Downloads
atpm.com
Review of Sigma Chess Lite 5.12, Vanessa Chess 2.01, with tournament results.
ExaChess vs. ChessBase
exachess.com
Virginia Chess Federation review compares these two Mac chess databases, favors ExaChess