Silverlight is a cross platform web/multimedia run time space. Other technologies in this space including Adobe Air (runtime environment for building rich Internet applications, using Adobe Flash, Adobe Flex, HTML and Ajax) and JavaFX (JavaFX Mobile is of particular relevance).
The Silverlight runtime for Symbian S60 5th Edition is hosted in the S60 default browser only (WebKit-based). All S60 5th Edition devices such as Nokia 5800 XpressMusic, Nokia N97 and Nokia N97 Mini are supported.
Microsoft Silverlight For S60v5