.CTO

.CTO file extension

This is the basic program to work with .CTO extension

ChessBase Light 2007

ChessBase Light 2007 ChessBase openings book

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

.CTO extension is also supported by the following programs:

ChessBase 9

ChessBase 9 ChessBase openings book

ChessBase

ChessBase ChessBase openings book

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

ChessBase Reader ChessBase openings book

Read chess games written in various formats and display them on a chess board.