Study the ICC's online database of over four million master games available nowhere else. You can search by player, opening, and other parameters. Examine them online or email them to yourself.
When you are in examine mode, attaches a note to the current move.
You can see the annotations using the "pgn" command. If you save your
examined game using "libkeepexam", your annotations will be saved with
it. Then when someone plays through the game, they'll be shown the note
as they get to each move that has one.