Custom Validation

with IValidatableObject, can be done with custom Custom Validation
attribute that derives from ValidationAttribute.
Display Annotations
Javascript and Ajax

Deleting some unused scripts
Managing scripts

Using online CDN for faster load time
Adding a razor helper
Adding App_Code folder
Adding scripts at the botom of the view and rendering a section with
scripts that are specific for a view.
Ajax.ActionLink

Adding class Queries
Adding progress loader gif and div progress with css