Orchard is a free, open source, community-focused project aimed at delivering applications and reusable components on the ASP.NET platform. It will create shared components for building ASP.NET applications and extensions, and specific applications that leverage these components to meet the needs of end-users, scripters, and developers. Additionally, we seek to create partnerships with existing application authors to help them achieve their goals. Orchard is delivered as part of the ASP.NET Open Source Gallery under the Outercurve Foundation. It is licensed under a New BSD license, which is approved by the OSI.
More information at http://orchardproject.net