Silverlight (formerly WPF/E)

It is an alternative to Flash, a light 2 megas byte plugin, for which the net surfer is asked to install on its client computer and that supplements the navigator with a graphic interface running in interaction with the server.
It is in fact a subset of WPF, reduced to be portable.
With Silverlight one can create RIA, Rich Internet Applications, and make astonishing interfaces, that can integrate animations and videos.

It offers to navigators the graphic features of WPF and which are of the same order as the ones of Flash, the plugin from Adobe.
- Make use of XAML,
- 2D vectorial graphics with scaling of objects.
- Works with Ajax thus JavaScript, DOM and XMLHttpRequest.

Silverlight also functions in local mode under the .NET environment. On the Web, the controls are exposed to Internet Explorer through Active X while Firefox and other browsers use the Mozilla plugin technology.

Features of Silverlight

HTML Integration

Silverlight is programmed in Javascript. It uses DOM to access elements of the page and JavaScript events for building the graphic objects of Silverlight.

XAML

XAML is the markup language that describes the graphic interface.
One can generate XAML code from data on the server, and thus create a dynamic application. The method createFromXaml called in Javascript builds the graphic components (widgets) on the page.

Vectorial graphics

The size of images does not degrade their precision. One can reduce or increase the size but preserve a perfect image.
The runtime is fast enough to use a video as texture of a 2D object.

Videos

It supports video files in wmv format, in high definition. Several videos can run at the same time and a certain interactivity, as zooming, is possible.

Compatible

Completely compatible with WPF, the graphic platform of .NET and Vista. But WPF has 3D graphics. One can thus re-use an application designed for the Web in a local environment.

Flash-killer

The Flash format of Adobe (formerly Macromedia) became a standard on the Web. It makes it possible to add graphic applications to the navigator, once downloaded the plugin. It is also used for Web applications, in particular by the Laszlo framework.
Microsoft hopes to replace it with a product adapted to modern technologies of the Web. It is also a plugin, but lighter and that runs on main navigators also.
However Flash runs under Linux while Microsoft provides only a runtime for Windows and Mac. Microsoft has announced however, at the convention of the National Association of Broadcasters on April 15; that it would provide information to Linux developers to support Silverlight. Actually, a project of Silverlight for Linux, code-named Moonlight has been started on the Mono website.

Programming

Microsoft will produce a set of tools called Expression, equivalent of the Creative Suite software from Adobe. Visual Studio will also make it possible to produce Silverlight applications.
Silverlight's controls can be used in several ways: they are first defined with an OBJECT or EMBED tag, or a script, or loaded from an XAML file, or an XAML content is created dynamically. And once created they are used in JavaScript.

Platforms envisaged

- Windows XP with SP2.
- Windows 2000.
- Windows Vista.
- Mobile Windows.
- Macintosh.
- Linux. Third-party plug-in.

Versions available in April 2007

- Windows XP with SP2.
- Windows Vista.
- Macintosh.

Resources

• XAML Tutorial. Using XAML on the Web with Silverlight or in desktop applications.
• Silverlight. Home page from which to download the plugin and demonstrations, on the Microsoft's website.
• Getting started with Silverlight. Tutorial by Microsoft.
• Create your own project. Start a Silverlight project.
• Silverlight.net. Microsoft has a website dedicated to the technology.