PEAR MDB2 is a merge of the PEAR DB and Metabase php database abstraction
layers.

Note that the API will be adapted to better fit with the new php5 only PDO
before the first stable release.

It provides a common API for all support RDBMS. The main difference to most
other DB abstraction packages is that MDB2 goes much further to ensure
portability.

Currently supported RDBMS:
MySQL
PostGreSQL
Oracle
Frontbase
Querysim
Interbase/Firebird
MSSQL
SQLite
Other soon to follow.

WWW: http://pear.php.net/package/MDB2/