SQL Dumpster - Free SQL scripts for website and application developers. - http://www.sqldumpster.com/
JCC's SQL Standard Page - A source of information about SQL standards. - http://www.jcc.com/sql.htm
SQLinForm - A free web-based Java tool to format any SQL statement independent from their Database. It can also prepare SQL statements for Java, C#, VB, ASP. - http://www.sqlinform.com
The SQL Summit: Understanding SQL/XML and Information Retrieval - Portal site with information about databases, SQL/XML, XQuery, modeling, information retrieval, and web and grid data access. The site includes articles, papers, and audio and video programs. - http://www.sqlsummit.com/
UESQLC (Universal Embedded SQL Compiler) - An embedded SQL-92 precompiler for C++ and Java, designed to be extensible using SGML documents. [Open source, GPL] - http://www.uesqlc.org/