If you have apps using Silverlight, this is the year to plan and move them to HTML5.  ESRI plans on deprecating ArcGIS APIs and Viewers for Silverlight, and Google plans to remove support for NPAPI (and therefore Silverlight) in Chrome.  Note that IE and Firefox will still support Silverlight for some time.

If you have apps built on Geocortex technology, it is time for you to move to HTML5 for sure.  Watch this video from a past webinar to help get your applications where they need to be for the transition.

Also read this document from the webinar Q&A.