Form and windows Authentication

An extended application need to be created for extranet giving authentication by SQL database.
http://msdn2.microsoft.com/en-us/library/bb975135.aspx

SharePoint Silverlight Browser

TrippleWood : A SharePoint Silverlight Web Part which displays SharePoint Documents and Pictures in a rich Silverlight flow control.
http://www.triplewood.com/triplewood/html/SharePoint2007.aspx