ADOdb is a database abstraction library for PHP. The PHP version currently supports an amazing number of databases, thanks to the wonderful ADOdb community: MySQL, PostgreSQL, Interbase, Firebird, Informix, Oracle, MS SQL, Foxpro, Access, ADO, Sybase, FrontBase, DB2, SAP DB, SQLite, Netezza, LDAP, and generic ODBC, ODBTP. The Sybase, Informix, FrontBase and PostgreSQL, Netezza, LDAP, ODBTP drivers are community contributions. Here is the complete list of drivers.

• Designed for speed. It is probably the fastest open source database abstraction library available for PHP.
• Provides extensive portability support such as date and type-handling and portable schema creation. See portable sql tips
• Support many enterprise features such as database backed sessions (with session expiry notification), SQL code generation, pivot tables, SELECT LIMIT emulation for all databases, performance monitoring.
• Easy to learn, especially if you have Window's programming experience, as it uses many ADO conventions.
• Extensive QA, every release is unit-tested on Access, MySQL, PostgreSQL, MS SQL, Oracle 9.
• Mature, continiously developed since August 2000. Has a large community of users.
• Very reasonable licensing terms (BSD). This means that you can incorporate (and even compile) it into your software applications royalty-free without asking the author's permission, provided you include license.txt in your release. Also dual-licensed (Lesser GPL).