What for System.Web.Extensions?

By default ASP.NET 3.5 Web App project has references to assemblies System.Data.DataSetExtensions.dll and System.Web.Extensions.dll.With System.Data.DataSetExtensions everything is clear for me, it contains...

ComponentOne excel and asp.net MVC

I am working on a action that returns excel file – the excel is created using ComponentOne dll.Here is what I have so farpublic ActionResult DownloadExcel() C1XLBook testBook = new C1XLBook();...