I just LOVE, yes I said love subsonic. Its one of the best open source frameworks I have ever used. I doubt I'll ever take on a project again without using SubSonic unless I don't have any other choice.

Ok so what is SubSonic? Here's a quote from their site:

A Super High-fidelity Batman Utility Belt. SubSonic works up your DAL for you, throws in some much-needed utility functions, and generally speeds along your dev cycle.

And it really is all of that. For those who don't know, a DAL is an abbreviation from Data Access Layer which means its a bunch of classes you interact with so that you don't have to (even though you still can) directly deal with SQL queries to your database ie. it encapsulates all your database functions.

To get started, download the installation from here and have a look at this introduction video.

Most developers are worried that performance becomes an issue once you use a generated DAL but SubSonic has been put through numerous test and I have also used it in a lot of medium sized web sites without any problems. Although I haven't worked with NHibernate before, I hear its a similar concept except that NHibernate is a mission to get set up initially (without 3rd party tools) and also a lot more effort to maintain.