Currently there is an issue with the RSS feed that is used by the mentioned online demo and that is why it is not available now. Due to the complexity of the RSS feed issue, I cannot provide any ETA when it will be fixed.
For the time being you can inspect the demo locally - from the installation folder of your Telerik UI for ASP.NET AJAX Live Demos. For you convenience I have also attached the demo files to this post.
Please excuse us for the caused inconvenience.
If you want to get updates on new releases, tips and tricks and sneak peeks at our product labs directly from the developers working on the UI for ASP.NET AJAX, subscribe to the blog feed