Last year Microsoft announced the availability of a major platform called Silverlight (formerly known as WPF/e or Windows Presentation Framework Everywhere). In Microsoft’s words, Silverlight is a "cross-browser, cross platform technology for delivering rich web experiences to end-users, including graphics, audio, video and animations."  Essentially, Silverlight is a browser-based, graphical display system built to deliver rich user interfaces.

When reading the technical magazines and the blogs you’ll find that many see Silverlight as a rich media competitor to Adobe Flash. However, Silverlight could be the beginning of something much larger. Silverlight marks the start of a new generation of web applications.

So, why is Silverlight such a big deal?  To understand this we have to go back in time about 10 years. At this time client/server technologies were all the rage. Typically, the client-side of these applications was developed on Windows (Windows 95 & 98). This resulted in Windows applications (today we call these WinForms) that featured rich, responsive and predictable Windows user interfaces.

Then came the Internet. Developing web applications was hard in the early days because there were no clear design standards in this new stateless, page-based world of the browser. Web applications were based on HTML which supported a very limited set of controls (textboxes, radio-buttons, etc.). Absent were the standard 'File, Edit, View' menus of today.

Now fast forward to 2008, to the evolved web. Advanced techniques involving CSS, DHTML, and JavaScript/AJAX have greatly improved the web user experience. However, the fundamental basis is still HTML, which never reached the level of UI richness found in prior Client/Server Windows applications. Silverlight changes this - going beyond traditional Windows interfaces.

A New Programming Model

Silverlight is a subset of the Windows Presentation Foundation (WPF). WPF is a new graphical display system that paints the actual pixels on the screen. Windows Vista uses WPF providing the beautiful visual effects such as transparency, anti-aliasing and animation.

WPF is optimized for Windows and is only configured to run on computers with the Windows operating system.  Silverlight, on the other hand, is cross-platform and runs on Windows, MacOS and one day perhaps even Linux.  It runs as a lightweight plug-in in the browser and supports all modern browsers including Internet Explorer, Firefox, Safari and Opera.

While running in the browser, Silverlight's components are programmatically accessible from JavaScript. This means a developer can add functionality that allows user interaction with the graphical content. For example, a dynamic chart may display when a user selects a stock, or a product can be added to a shopping cart with an accompanying animation.

Indeed, most of this is possible today with Adobe’s Flash.  However, Silverlight 1.1 offers an even more flexible programming model that includes support for C# and VB.NET (on the browser!). This allows web developers and designers access to a mature and robust .NET Framework on the browser. 

It would be a mistake to see Silverlight as a singular, stand-alone technology. It's part of a continuum of related technologies. First of all, it is built on a mature .NET foundation with object-oriented languages including C# and VB.NET.  Secondly, Microsoft released a suite of tools called Expression, with the purpose of making design and development in this new generation of web applications easy. Finally, a related technology called XBAP, allows true WPF Windows applications to be deployed on the web (running on IE in a security sandbox).

Silverlight is a new platform, and its first incarnation does not necessarily go beyond tools like Flash.  However, this is the first step towards a world where the differences between web and Windows applications are going to fade and dissolve.

The Future

We can only speculate what the future holds. It is clear that we are going to see a transition to a new generation of web applications that users are going to love and likely expect. We predict companies will find it hard to start up new web development projects that do not benefit from Silverlight and related technologies.

With the release of Silverlight, Microsoft laid the technical foundations for a major shift in web application development. Eureka Software is very excited about these changes and the opportunities it brings. We hope you are too. Let's enjoy the ride.