.CPO file extension

This is the basic program to work with .CPO extension

ChessBase Light 2007

ChessBase Light 2007 ChessBase Opening Key

The program works with the following extensions: ck3, cko, ckn, cba, cp1, cbb, cp2, cbc, cp3, cbe, cpn, cbf, cpo, ctb, cbh, cbm, ctg, cbp, cto, cbt, pgi, cbv, pgn, cib, cbz, cit, ck1, ck2, cbs and cbgi

.CPO extension is also supported by the following programs:

ChessBase 9

ChessBase 9 ChessBase Opening Key


ChessBase ChessBase Opening Key

ChessBase 13 is a personal, stand-alone chess database.
ChessBase Reader

ChessBase Reader ChessBase Opening Key

Open chess games database files and play through the games.