In this blog post Jeff Prosise talks about Silverlight's COM automation support and publishes a downloadable demo that uses Microsoft's speech automation server to verbalize error messages.
One of Silverlight 4's most compelling new features is support for out-of-browser applications with elevated permissions. An app running with elevated permissions can perform actions that a normal sandboxed application can not. For example, it can access the local file system, and on Windows boxes, it can interact with COM automation servers. This latter feature—also new to Silverlight 4—is the subject of this blog post.
Silverlight 4's ComAutomationFactory class provides an API for instantiating COM automation objects and for determining whether COM automation is available.