From ApexCalibur Software:
The AllDb class library for .NET Framework 1.1 provides the functionality for implementing any ADO.NET supported database using a single set of source code. AllDb provides a consistent interface across all databases. AllDb is a set of classes that encompasses all aspects of accessing databases within the ADO.NET architecture. It's designed to provide least-common-denominator support for either connected or disconnected database access.
AllDb has been implemented successfully with six of the most commonly used .NET supported databases: Microsoft SQL 2000, Oracle, DB2, Sybase SQL Anywhere, MySQL and Microsoft Access.