Gentle.NET is a database independent object persistence framework. It has an extensive feature set, excellent performance, and reasonably complete docs. Features include SQL generation, object construction/caching/uniqing, validation, and much more.
An Object/Relational persistence layer for VB6 and .NET (VB.NET,C#,etc) similar to ObjectSpaces etc. Database interaction is managed transparently at runtime and requires no SQL knowledge. Great performance, caching, flexible O/R mapping and more.