1)   DBDocumentor 4.20
Document and report on the SQL objects making up your SQL database. DBDocumentor describes all SQL objects in the database, and includes parameter, result set and data usage listings. Output options include colorized source code and XML.

 2)   SQLHelp 2.42
Annotate and document the SQL stored procedures driving your web application. SQLHelp describes the parameters, output result sets and transactional nature of each procedure. Output options include colorized SQL listings.

 3)   Apex SQL Doc 2005.11
Apex SQL Doc is a powerful tool to document your sql server database into HTML and CHM help Documentation including VS2005 style and HTML 2.0 support.

 4)   DBScribe for MySQL 1.1
Leadum DBScribe is a free powerful tool to document MySQL database into HTML, CHM help, MS Word Documentation. It supports: rich set of output formats and styles, wizard and command line interfaces, complete database structure documenting