Database and Book Editing

Bookup
Chess database program used primarily for modeling chess opening repertoires.
http://www.bookup.com/

Chess Position Trainer
Focusing on training openings. Provides downloads, testimonials, demonstration videos, and support. [Windows]
http://www.chesspositiontrainer.com/

ChessAssistance.com
Articles for ChessAssistant. Provides downloads, reviews, and FAQs.
http://www.chessassistance.com/

ChessPad
A free chess database program for Windows 95 and NT. Includes download, change log, and information on how to use in conjunction with Crafty.
http://www.wmlsoftware.com/chesspad.html

ChessVU
Features application downloads, screenshots, and installation instructions.
http://chessvu.netfirms.com/

ChessX | Free Chess Database
Free chess database for Windows, MacOS X and Linux. Lists features, screenshots, and development information.
http://chessx.sourceforge.net

ICOfY.net
Database of current and past events.
http://www.icofy.net/

Jose Chess Database
A database with a graphical front-end for viewing and editing games. Features screenshots, a manual, and downloads.
http://jose-chess.sourceforge.net/

Scid
Free chess database for Windows and Unix
http://scid.sourceforge.net/