ezSQL is an open source PHP database class that I wrote a while back. It’s used on over 100k websites and is the backbone of many open source projects such as WordPress. The class makes it ridiculously easy to use mySQL, Oracle8, SQLite (PHP), within your PHP script.
GreenSQL is an Open Source database firewall used to protect databases from SQL injection attacks. GreenSQL works as a proxy and has built in support for MySQL db. GreenSQL is a database security solution that can prevent SQL injections.
The ToscanaJ project is a collaboration between DSTC, the University of Queensland and the Technical University of Darmstadt to recreate a classic Formal Concept Analysis tool called Toscana and to give the FCA community a platform to work with.
PostGIS adds support for geographic objects to the PostgreSQL object-relational database. In effect, PostGIS "spatially enables" the PostgreSQL server, allowing it to be used as a backend spatial database for geographic information systems (GIS).