VistaDB 2.0 data engine for .NET has been released. VistaDB is the #1 alternative to Jet/Access, MSDE and Xbase for building small to midsize WinForms and ASP.NET database applications. Robust data engine with SQL-92 support features a small 1MB footprint, single-file data store, rich data types, billions of rows per table, transaction processing, managed ADO.NET Provider, VCL components, visual utilities, XCOPY deployment, zero configuration with free unlimited distribution, and much more.

More info: http://www.vistadb.net