SubSonic is A Super High-fidelity Batman Utility Belt that works up your Data Access (using Linq in 3.0), throws in some much-needed utility functions, and generally speeds along your dev cycle.
SubSonic 3.0 is the latest version of SubSonic and was released in June of 2009. Work on SubSonic 3.0 lasted close to a year, and revolved mostly around supporting Language-integrated Query, also known as LINQ.
The focus of SubSonic 3.0 is to provide tools, not guidance or an overall mindset/approach. There are a number of things in SubSonic that allow you to move faster while applying whatever patterning floats your boat. We're not as complete as NHibernate, but you'll work faster with less concept count. We're not as deep as Linq to SQL, but you can use our stuff on most databases.
Linq
SubSonic 3.0 supports Linq with a core Expression Parser that turns System.Linq.Expressions into SQL. In addition, our 2.0 Query Tool (now called SimpleQuery) can use Lambda expressions to simplify some tasks.
All of the templates we use build on top of our core parsers and query tools, and you can build on top of these quite easily.
Simple Query Tool
The Simple Query Tool works almost exactly as it did with SubSonic 2.x - as a fluent "SQL-style" query tool that allows you to query the database almost as if you're using SQL.
The additions to this tool include Expression support for Where's as well as a "ToList<>()" method that will execute a query and load an object for you.
Utilities
SubSonic also comes with a number of utility methods expressed as Extension Methods. This is SubSonic's Sugar Utility Library and has a number of things to save you time, including File IO, string methods, date math, number utilities, and Object parsing.