ver the years, we have all seen the proliferation of Web applications. In the early days, Web sites consisted of sets of static HTML pages, with nice graphics and lots of information. Then, server-side technologies like CGI, ASP, and JSP made Web applications possible and suddenly users were able do a lot of things on the Web, such as buying products online, performing reservations, etc. Client-side innovations, such as JavaScript, helped to improve the user experience of Web applications, making them feel much more responsive. Although AJAX's underlying technologies had been available for several years, it wasn't really until the last couple of years that people really started spending more time AJAX-enabling their Web applications. All this boils down to one important goal of Web developers—making Web applications much more interactive and responsive.

Today, a new term has been coined—RIA, which stands for Rich Internet Applications. To Microsoft, RIA really stands for Rich Interactive Applications. And it is with this in mind that Microsoft recently launched a new technology/product known as Silverlight. Previously known as Windows Presentation Foundation/Everywhere (WPF/E), Microsoft Silverlight is a browser plug-in that enables developers to host Rich Internet Applications (RIA) that feature animation, vector graphics, as well as video playback.

This article will help you get started with Silverlight and hopefully give you a good feel for how Silverlight development works.

The State of Silverlight
At the moment, there are two release versions of Silverlight: 1.0 (released) and 1.1 (in alpha release), the main difference being the support of .NET languages in version 1.1. For version 1.0, you have to use JavaScript for writing your application logic. In version 1.1, you can also use either C# or Visual Basic for your application logic, which is then executed by a version of the CLR built within the runtime.

The Silverlight runtimes currently support the following browsers:

• Internet Explorer 6/7
• Firefox 1.5/2.0
• Safari 2.0

This article focuses on Silverlight 1.1