I understand that silverlight has come a long way since its inception, but I have always struggled to find the business need for silverlight. What are the advantages and disadvantages of silverlight 4.0 vs modern html5 and javascript libraries like jQuery or ExtJS?
Should i use silverlight or a combination of html5 and javascript for my ui?
This question is going to be nuked by the question nazis. But it's a valid question, if phrased a little argumentatively.
A plugin free web is of a little value in itself. Just about everybody has flash installed, and I suspect the same will one day be true of Silverlight. If the benefit to the user is there, they won't mind installing a 5MB plugin.
So what does Silverlight offer that HTML 5 and javascript do not? A development model that doesn't suck. Seriously. It gives you a stripped down version of the windows desktop programming model. Creating software is faster, easier, and cheaper for Silverlight than it is using open web technologies. The software loads faster, runs faster, looks slicker, and you can do things that you cannot with just a browser. It's so nice to just target one platform instead of the hodgepodge that is the browsers that make up the internet (although in recent years this has become considerably less painful, it's still a mess.) So as a developer who's done a lot in both Silverlight and HTML/css/jQuery, I'd say I'd rather see a Silverlight dominated web than the "open web" any day. No I don't trust Microsoft, but neither do I trust glacially slow standards committees. Silverlight is seeing a new release every 6-10 months. HTML 5 is still vaporware. This is my opinion based on personal experience and some anecdotal comparisons of desktop vs web application development costs.