Chess::PGN::Parse offers a range of methods to read and manipulate
Portable Game Notation files. PGN files contain chess games produced by
chess programs following a standard format
(http://www.schachprobleme.de/chessml/faq/pgn/). It is among the preferred
means of chess games distribution. Being a public, well established
standard, PGN is understood by many chess archive programs. Parsing simple
PGN files is not difficult. However, dealing with some of the intricacies
of the Standard is less than trivial. This module offers a clean handle
toward reading and parsing complex PGN files.

A PGN file has several tags, which are key/values pairs at the header of
each game, in the format [key "value"]

After the header, the game follows. A string of numbered chess moves,
optionally interrupted by braced comments and recursive parenthesized
variants and comments. While dealing with simple braced comments is
straightforward, parsing nested comments can give you more than a
headache.