Silverlight

Introduction to Silverlight
Published: 23 May 2007
By: Steve Orr
Silverlight is Microsoft's new Flash Killer but it will be so much more! Learn all about the present and future features of Microsoft's new web front end.
What is Silverlight?
Silverlight is a browser plug-in that that extends the web development experience far beyond the limitations of plain HTML and JavaScript. Being a Microsoft product, you might expect it to work best (or only) on Windows and Internet Explorer. So you may be pleasantly surprised to know that it works equally well on Windows and on the Mac, and it also works equally well on the Firefox and Safari web browsers. Since Silverlight is a client side technology, it doesn't matter what backend server software or platform you're running - even Apache/Linux will do just fine.
Version 1.0
Silverlight version 1.0 - scheduled for release this summer - is very comparable to Adobe Flash. It delivers high performance multimedia and animation capabilities that can blend seamlessly with HTML. It's capable of playing a variety of audio and video file formats, such as MP3, WMA, and WMV. It handles streaming quite well, so media can start playing immediately without having to wait for the entire file to download.
Silverlight's user interface is defined with a subset of XAML - an XML format shared with Windows Presentation Foundation (WPF). This facilitates vector based animations, a claim that goes beyond Flash's current capabilities. Silverlight's compiled object model can be navigated via JavaScript for seamless interaction between embedded Silverlight components and the page that hosts them.
When users encounter a Silverlight 1.0 enhanced web page for the first time, they'll be prompted with the quick & easy installation that's only about a 1.2 megabyte download.
You can download the beta version of Silverlight 1.0 now.
Version 1.1
While the multimedia and animation capabilities of Silverlight 1.0 are certainly great for graphic designers, Silverlight version 1.1 (currently in alpha) starts to provide the kind of business oriented functionality that the majority of web developers need.
Probably the most exciting feature of version 1.1 is the built-in cross platform subset of the .NET Framework. While you can still mix in as much (or as little) JavaScript as you'd like, you'll now have the option of running your own fully compiled .NET code within IE, Firefox, or Safari. Those developers who hate JavaScript should be thrilled to know they can now write their client side code in C#, VB.NET, or any other .NET language. This .NET code can interact with the browser's object model so it can manipulate the page's HTML in addition to interacting with any Silverlight user interface that may be embedded in the page. You'll now be able to replace slow performing JavaScript code with fully compiled .NET code that could easily execute hundreds of times faster.
A variety of useful classes are included in Silverlight 1.1 for working with cutting edge technologies like LINQ, generics, multithreading, and invocation of Windows Communication Foundation (WCF) web services. There's also support for XML manipulation, networking, I/O, collections, globalization, and JSON serialization.
ASP.NET support is also provided for things like personalization, profiles, role membership, and invocation of ASMX web services. On a related note, the next release of ASP.NET is expected to include a variety of tools for easing Silverlight development, including built-in controls that make it easy to embed Silverlight content.
Unfortunately there are currently no definite plans to include any significant number of controls in Silverlight 1.1 - not even a basic button control is currently in the mix. They do at least provide a control class that can be used to build your own controls, and alternately it's not terribly difficult to make basic controls using XAML and some custom code - but certainly we'd prefer not to have to write such basic code. Luckily there are several controls available in the separate Silverlight 1.1 Alpha SDK download.
Since Silverlight 1.1 is still only in alpha, its uncertain exactly what other functionality may ultimately make it into the release version. The current download size for this far more functional version of Silverlight hovers at around 4MB.
Future Versions
From my conversations with Silverlight mastermind Scott Guthrie and his merry band of genius underlings, they've got a lot of mouthwatering functionality planned for upcoming versions of Silverlight. General themes include a rich set of built-in controls, data binding support, XLINQ, RSS, Xml Serialization, Opera support, and improved layout management. And that's just for starters.
In general the vision is to transform Silverlight from its current 1.0 state of multimedia powerhouse into a highly productive business tool capable of powering rich applications of virtually every kind.
Even with all this extra functionality, Silverlight's team has a long term secret goal of keeping the download size under 5MB. Shhhh! Don't tell anybody!
Development Tools
Currently the lack of polished tools for developing Silverlight applications is its biggest hindrance. The next version of Visual Studio (codenamed Orcas) is expected to ship with rich Silverlight support. However, the current beta version of Orcas clearly still needs a lot of work before achieving this goal. If you're brave enough to be tinkering with the Orcas beta then you might as well download the Silverlight Tools Alpha add-on to try out its Silverlight development capabilities.
Microsoft's new Expression suite of products is currently closer to being in a finished state. They are presently more polished and less buggy than Orcas. Specifically, Expression Blend is probably the most valuable Expression product for Silverlight development. However, be forewarned that the Expression suite is intended more for graphic designers than software developers. Therefore Visual Studio-oriented developers should expect a significant learning curve.