Adam Nathan is a senior software development engineer in Microsoft’s Developer Division and author of Silverlight 1.0 Unleashed on which this article is based. Copyright 2007 Sams Publishing, All Rights Reserved.
Despite all the wonderful things you can say about HTML, CSS, and JavaScript, I think most people doing a lot of web-based development would agree that they form a pretty poor environment for developing modern sites and applications. If you care about your content working on most web browsers (or even just Internet Explorer and Firefox), accommodating their differences can be maddening. Many techniques and JavaScript libraries have been developed and shared over the years that can reduce this frustration, but none of them are silver bullets.
In addition to browser differences, the graphical capabilities of HTML are too limiting for many user experiences that people want to create. Drawing a simple line, incorporating video, and a number of other things are extremely difficult or impossible with HTML alone. It's not that these technologies were poorly designed, but simply that they were designed for hyperlinked documents rather than the extremely rich presentations that most people want to create on the Web these days.
Considering these issues, it's no wonder that Adobe Flash has been so successful. Whether someone wants to create a professionally designed website, an online game (or any number of other applications), or even a simple advertisement, Flash has been a natural choice for escaping the limitations of HTML. If you doubt the pervasiveness of Flash, try this experiment: Think of a brand of food you eat, and then navigate to the brand's website. Chances are you'll find Flash content at your destination. (I just tried pepsi.com, doritos.com, and oscarmayer.com, and all three are using Flash at the time of writing.) The Flash development experience leaves much to be desired, however. Flash (the runtime environment, as well as the tool) suffers from the same basic problem as HTML: Many people are trying to use it for creating rich applications, but it was originally designed for something else (in this case, simple animations).
This is why the introduction of Silverlight is so exciting. A promising alternative to Flash, Silverlight enables the creation of rich web content and applications using a lightweight add-on that is friendly to both designers and developers. Yes, the first version of Silverlight is primitive in areas, but it's a true development platform based on concepts and APIs introduced with Windows Presentation Foundation (WPF) in 2006 and in development for many years prior. And, unlike just about any software that has come out of Microsoft, Silverlight is a small download! Version 1.0 is less than 1.5MB, so users who don't have it can get it pretty quickly when browsing to Silverlight content. (By default, Silverlight also automatically updates to later versions when they are available.) Silverlight might just be the silver bullet many designers and developers have been waiting for. Silverlight 1.0 applications are created with a mixture of XAML (Extensible Application Markup Language), HTML, and JavaScript, so they are easy to integrate into existing web content and compatible with popular Asynchronous JavaScript and XML (AJAX) libraries and techniques. XAML is an XML-based declarative language. In typical Silverlight applications, a XAML file contains a hierarchy of visual elements that must be rendered on the screen. Silverlight parses the XAML content on initialization, and then renders the content as appropriate.
