There are many ORM options out there in the .NET landscape: NHibernate, SubSonic, LINQ to SQL, Entity Framework, etc. But there is still room in the space for low-friction tools. With that in mind...Echo is a lightweight ORM tool that targets small to medium sized .NET web applications.
It implements the following features:
Code generation with open source code generator MyGeneration. All generated classes are partial so you can easily extend them. Persistence ignorance mechanism. A fluent-interface query builder capable of generating complex SQL statements in code (including complex joins, sub-queries, and even full-text search queries). Extremely small footprint, the base classes are very thin which allows for quick ramp-up and extensibility. Fully maps table relationships including support for "join through" relationships implemented with a join table. Controller pattern that abstracts persistence logic away from business entities. Strong yet simple validation system allows adding custom validators to an entity. Add behaviors to entities without overriding methods like Save, Delete, and Update. Provides for dynamically targeting multiple data sources without tying any particular entity to a connection string. Entity-Attribute-Value (EAV) pattern wrapper. This allows you to create a plain .NET object, inherit from IEAVEntity and be able to automagically save and query this object form the database. All you need is an EAV style table that can act as a repository. This feature is really geared toward rapid prototyping.
These details are provided for information only. No information here is legal advice and should not be used as such.