Sharp Serialization Library serializes and deserializes primitives, ArrayLists and Hashtables, compatible with PHP serialize(). Use it for SOAP/Web Services communications where Hashtables cannot be passed otherwise, or saving to a file readable by php.
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.
PersistMe is a .NET O/R mapper whose main focus is to be simple to use, adaptable to your software code patterns (not the other way) without sacrificing power and robustness. PersistMe Can be used by any .NET programming language (C#, VB.NET, etc).