SQLite

• SQLite   - Cross-platform C library that implements a self-contained, embeddable, zero-configuration SQL database engine. The site offers user and developer documentation, downloads, a wiki with additional embedded and linked information and mailing list archives.[Public Domain]

• PEAR :: Package :: DB_Sqlite_Tools - An object oriented PHP interface to manage and backup Sqlite databases.
• Pysqlite - A Python interface using the SQLite embedded relational database engine that conforms to the Python Database API Specification 2.0. [Open Source, zlib/libpng license]
• SQLiteDB - Simple PHP SQLite class written in PHP for enabling SQLite database management directly from within PHP scripts [Open Source, GPL].
• System.Data.SQLite - ADO.NET 2.0 Provider with VS 2005 design-time support. Available for standard and Compact Framework. Downloads and a forum are available.