jMVC.NET is an open-source control library for ASP.NET developers. It provides a simple but powerful client-side MVC engine which makes it easy to develop dynamically-changing user interfaces.
jMVC.NET is most useful when the structure or number of your controls changes according to the data entered or selections made, and you don't want to do postbacks or AJAX trickery to make it happen.
To get a feel for how you can drop a jMVC.NET control into your existing ASP.NET application, see these examples. They range from super-simple to fairly advanced, but in all cases (except for "Hello World") are probably neater and simpler than any server-centric native ASP.NET implementation of the same behaviour.
You will need to understand some Javascript as the templating language is actually just Javascript in disguise, and the client-side controller code is obviously Javascript too. The server-side code is written in C# here, but there's nothing to stop you using jMVC.NET with VB.NET just the same.
For a tutorial on implementing a dynamic list with jMVC.NET, see this blog post.
For more about the templating language jMVC, including its syntax, see this blog post.