A File Upload/Download Control/Component by Xceed Software Inc

Features:
.NET technology
- Created with Silverlight 2 Beta 1, will be updated for future versions of Silverlight 2 as they become available.
- Written entirely in C#.
- Complete source code is available in the Blueprint Edition.
- Based on a flexible and extensible object model.
- Comprehensive documentation fully integrated into Visual Studio is provided.
- Includes a variety of VB.NET, C#, and JavaScript sample applications to get you started.

Major Features
- Lets you quickly and easily add upload capabilities to any Silverlight 2 Beta 1 application.
- All upload operations are asynchronous, so the hosting Web page remains perfectly responsive and usable throughout the transfer.
- Multiple files can be uploaded in a single transaction.
- Uploading field contents and strings from your Silverlight forms to the Web server is simple: fields are automatically gathered and formatted into a standard request.
- Helps you deliver a beautiful Silverlight 2 experience to your end-users, such as displaying progress information.
- Lets you compress data as it is being uploaded. Supports GZip and Deflate, with controllable compression level.
- Rich events let your application monitor and control every step of an upload operation.
- Several versions of the upload methods are provided: from simple “fire-and-forget” versions to ones letting you control everything. Static and instance versions let you use the component to suit your needs.
- Uploads can be deferred, letting your application gather files and strings and then perform the actual transfer when ready.
- The HTTP requests produced by the component use the standard MIME format for uploading data through the “multipart/form-data” content type, meaning any modern Web server should be able to handle the data.
- Custom HTTP request headers (main and item headers) can be set.
- The boundary used in the HTTP request can be specified.
- Base64 encoding is available to support Web browsers that do not allow the upload of non-ASCII data.

Included helper server classes
- Xceed Http Server Tools for ASP.NET is provided to help deal with compressed/encoded data.
- The UploadedFile and UploadedFiles classes seamlessly handle compressed/encoded files: because these classes are based on the FileSystem Core, they make dealing with such files as easy as working with regular files.
- The UploadedString class helps simplify handling compressed/encoded strings.

Other features
- Client-side execution: no server-side component or code required if compression or encoding isn’t used.
- Tested with IIS, but is compatible with any HTTP 1.1 standards-compliant Web server.
- Does not trigger a page refresh during or after an upload.
- Supports Unicode filenames.
- Supports Windows Vista, Windows XP SP2, Windows 2000, and Windows Server 2003 (except IA-64), and runs in Internet Explorer 7 and 6, Firefox 2 and 1.5, and Safari (Mac OS 10.4.8+ only). Some OS/browser combinations are not supported by Silverlight.