ChessX is described as 'Open source chess database'. There are more than 10 games similar to ChessX for a variety of platforms, including Windows, Mac, Linux, Online / Web-based and Android. The best alternative is Lichess, which is both free and Open Source. Other ChessX like games are Scid vs. PC (Free, Open Source), Chessmaster (Paid), OpeningTree (Free, Open Source) and Brutal Chess (Free, Open Source).
josé is a graphical Chess tool. You can store chess games in a database (backed by MySQL). You can view games and edit variations and comments. You can play against a "plugged-in" chess engine and use it for analysis.
3D Super Chess offers a beautiful and customizable chess experience featuring both 2D and 3D environments. Play against a challenging virtual opponent or friends in PvP mode on the same Mac. Thanks to the rotating chessboard you'll always stay on top of things.