Kokopu is a JavaScript library for chess applications. It implements the chess game rules, and provides tools to read/write the standard chess file formats (PGN, FEN, etc.).
RPB Chessboard
RPB Chessboard is a plugin for WordPress. It allows to typeset and display chess games and diagrams on posts and pages of WordPress blogs, using the standard FEN and PGN notations.
RPB Calendar
RPB Calendar is a plugin for WordPress. It allows to list and schedule events in WordPress blogs, and to display them in a calendar in a post or a page.
Virtual Chess Clock
Virtual Chess Clock is a chess clock software: it turns your computer into a chess clock. VCC is designed to be easy to use. It is free, open-source and works both on Windows and on Linux.