Configurable custom providers to support most any database without recompiles, user controllable transactions and tracking, stored procs for relationships, typed datasets, and more.  A big thank you goes out to Allan Ritchie, Gerrod Thomas, Jerry Shea, and Paul Welter for their contributions -- see the read more link for more details.

• Define your own CustomProvider for any Database without Recompile
• MySql, PostgreSql, Sqlite, Firebird, DB2, VistaDB, SqlCe, Sybase
• Control your own Transaction object with BeginTransaction method
• Interact with the Transaction in the IObjectNotification events
• Control over all Caching with EndTracking and ClearTracking methods
• Set optional entity autoTrack="false" and use StartTracking instead
• New ILoadOnDemand Interface for Lazy-Load with IsLoaded and Resync
• Support for Typed Datasets which some Reporting Packages Require
• Support Stored Procedures for Relationships -- Needs More Testing
• ORHelper: Create Single Entity Mappings -- Or CodeSmith Templates
• Peer Support: New Private and Unmoderated Subscriber-Only Forums
• MS ObjectSpaces: BeginTransaction, EndTracking, and ILoadOnDemand
• Fixed Resync to work with Child Relations -- Minimize Resync Need
• Do Not Require LazyLoad for Recursive Persistence of ObjectGraph
• Enable Null Many-To-One Parent Relationships -- Return Null Object
• Better Handle Value Type Conversions and Non-Int32 Auto Primary Keys
• Handle Invalid .NET DateTimes, Null Enums, and Access Guid Values
• Fixed Key Handling to Support Entities with Zero-Value Primary Key
• Fixed Optimistic Concurrency Inserts to work with any Setup Order
• Fixed ObjectSet/ObjectList RemoveByKey and Composite Key Tracking
• And a special thanks to each of the following contributors to v3.0:
  • Major Contributor: Allan Ritchie: Custom Providers,Transactions,
    EndTracking, Resync, and Relation Stored Procedures
  • Contributor: Gerrod Thomas - Resync and Tracking Issues
  • Contributor: Jerry Shea - Lots of Miscellaneous Fixes
  • Contributor: Ben Priebe - Typed Datasets, Null Parameters
  • Contributor: Paul Welter - Optional CodeSmith Templates
  • Also thanks to Sam Smoot, Nick Franceschina, and Jason Shigley