Telerik has released their extensions for asp.net MVC . Iâ€™ve used these extensions for a few projects and I really like the way they are setup. These extensions are a set of html helpers for asp.net mvc 1.0 (and 2.0).
These controls are provided free as open source. From the release notes:
1. New controls: TreeView, NumericTextBox components, Calendar, DatePicker
2. New Features: Grid grouping, editing and localization
3. Uses JQuery 1.4.2
Be sure to read the release notes to see all the functionality these controls provide.