Asynchronously running code can improve the overall performance and responsiveness of your web application. In ASP.NET 4.5 web forms applications you can register asynchronous methods with the page framework. The ASP.NET page framework and .NET 4.5 asynchronous programming support then executes the operations in asynchronous fashion. This article shows how this can be done.

For security reasons browsers don't allow cross-domain communication. However, in some legitimate situations cross-domain communication becomes necessary. A common work-around for this restriction is to use JSON with Padding or JSONP. In this article you will learn how JSONP can be used in an ASP.NET MVC application.

Unhandled exceptions in the Web API controller class are often indicated as HTTP status code 500, i.e. Internal Server Error. This generic error message is of little use to the client. Bipin Joshi explains how to use Web API to fine tune and customize the HTTP errors that are sent to the client browser.

HTML5 lets you drag files from Windows Explorer or Desktop and drop them on a predefined area of a web page, from where you can upload them to the server using jQuery.

Data driven web sites rely heavily on JavaScript and JavaScript based libraries such as jQuery. In situations where data binding and dependency tracking are desirable, open source libraries such as Knockout can easily fill these requirements in ASP.NET web sites. Bipin Joshi explains what Knockout is and how to get up and running with it in your ASP.NET applications.

The newly added bundling and minification features of ASP.NET 4.5 let you bundle and minify JavaScript and CSS files, to improve the performance of your web application.