I often hear this question a lot. What is difference between Silverlight and WPF?? Aren't they developed by Microsoft?? Why do they need to have two different technologies for developing application interfaces?? Why can't they just club them into one technology??

Well, the reason behind separating these two technologies is because they serve two different purposes.. Silverlight is developed with the intention of competing and eating into Adobe Flash's market. Today, Adobe Flash is undisputed king when it comes to developing rich web interfaces. And with Silverlight, they hope to get a pie of that market.. Knowing Microsoft for 3 decades, I wasn't surprised when they announced Silverlight... They compete with every tom, dick and harry and they are pretty good at that... (until they start messing with Google). 

Silverlight basically allows you to create web applications that have rich user interface. It has large array of tools, which developers can leverage to build cool and visually spell binding interfaces. Whereas, WPF is primarily developed for building Desktop applications.. Incidentally, WPF applications can be hosted on Web Browsers which offers rich graphics features for Web Applications...

Web Browser Applications (WBA) developed on WPF uses XAML (eXtended Applicatoin Markup Language) to host user interface for browser applications. The Web Server sends the XAML files ( which are stored as discrete files on the server) to the client, which takes the help of .NET 3.5 framework to render the HTML. It's not as complicated as it sounds, because all this logic is hidden from the developer and they only have to make user of rich WPF libraries to develop the application. Everything else is encapsulated... That's the whole purpose of Object Oriented Programming... isn't it???

Alright folks, that completes my blog. Mail me at reddy.preetham@gmail.com for further queries.