GroupDocs.Viewer for .NET is a web-oriented middleware designed to display over 50 different document types in a browser. It is a client-server library that converts documents into an HTML-compatible format and then renders them in a browser just as a regular web-page. As a result, you don’t have to install any third-party software or browser plugins on the client. Documents can be viewed from any modern web-browser, including IE8+, Chrome, FireFox, Opera, Safari 5+ and their mobile versions. Recently, we created a sample that demonstrates a basic ASP.NET document viewer implementation based on the GroupDocs.Viewer for .NET library. It also shows the core difference between two rendering modes available in GroupDocs.Viewer: image- and HTML-based. This can help you choose the right document rendering mode, depending on your specific requirements. The sample itself is a standard ASP.NET WebForms C# project that was created using Microsoft Visual Studio 2012. It contains two example documents (in PDF and Excel formats), but you can upload an unlimited number of your own documents in different formats to test the viewer. For more information on the viewer and supported file formats, please see this page, while the sample project along with its description can be grabbed from the code.msdn.microsoft.com sample gallery.