Blunder is an integrated set of tools to help chess players improve their game.

The core tools are mostly LAMP-based (Linux, Apache, MySQL, PHP). However, there are discrete components within Blunder which can be used outside of this framework.

Most of Blunder is released under the GNU GPL Version 3 license. A few parts are under other free licenses. See licensing for more details.

Live demonstration

Currently Blunder can be grabbed from git source control. The core web-php component has been in beta for some time, and has worked well. The Java jar file that converts chess PGN to FEN format is under active development, and just entered beta. We will release a tarball when the beta testing of the PGN to FEN converter enters completion. While we are putting finishing touches on the PGN to FEN converter, and beta testing the whole suite, Blunder is in quite usable condition right now - we have been using it for over a year to happy result.

Project details - Git source repository, discussion forums etc.


Most chess teachers say one of the main methods to improve your chess game is to look over your games, especially your tournament games, and look for where you made mistakes. Mistakes being mainly blunders and missed opportunities. Blunder was created to help in this endeavor, and we hope to automate the process more and more. See the live demonstration above to see how it works.