function supports_history_api() {
return !!(window.history && history.pushState);
}

a) The syntax is easy to understand
b) Syntax can easily be integrated into various templating systems
c) Syntax can easily be integrated into Content Systems

The only one that appears workable is the PICTURE tag, though “picture” isn’t the right word – “image” or “imageset” would be far more understandable.

As far as the code goes, using media-query style values is OK but surely it would be a lot simpler to use the browsers viewport [width] to determine which image is displayed?

I propose a “viewport” attribute, with the value being the minimum viewport size, eg in this example hires.png would only display if the viewport was at least 800px:


<picture alt="angry pirate">
<source src=hires.png viewport="800">
<source src=midres.png viewport="480">
<source src=lores.png>

<img src=midres.png alt="angry pirate">
</picture>


To me, as someone who develops web site for a living, this makes far more sense.

It will be great if also the server can continue the image download from a given point, in order to download higher frequency information when needed (for example in a resize). @pelicanorojo

– “My site is developed in Asp.net how much it will be beneficial to me if I convert it in to HTML 5?”

You don’t need to choose between ASP.NET and HTML 5. Microsoft is fully committed to HTML 5.

ASP.NET is part of the .NET Framework:
ASP.NET Overview

ASP.NET websites are typically composed of various .NET Framework components. The user interface has been traditionally designed using ASP.NET Webforms or ASP.NET MVC Views.

ASP.NET. Web Forms contain ASP.NET Server Controls which abstract HTML rendering to the ASP.NET runtime.

ASP.NET MVC provides the ability to design “closer to the metal,” exerting fine-grained control over HTML rendering: ASP.NET Web Pages with Razor Syntax.

Here is another programmer comparison of ASP.NET Webforms and ASP.NET MVC Views: 10-reasons-asp-net-webforms-still-rock.

Personally, I am using ASP.NET MVC using Razor Views. This provides the richness of the .NET Framework along with full control of HTML, CSS, JavaScript, etc.

I add logic to my ASP.NET MVC controllers which detects whether the HTTP Request originated from a mobile device:


if (Request.Browser.IsMobileDevice)
{
return View(viewName + ".Mobile", model);
}
else
{
return View(viewName, model);
}


I then create separate views for desktop and mobile devices, each containing unique navigation structures. I put content in partial views that can be re-used by both the desktop and mobile views.

For CSS, I use CSS media queries to detect the device and browser widths.

The end result is that a single URL will return HTML and CSS specific to the user’s device and browser width.

free Pluralsight training course on ASP.NET MVC, HTML 5 and jQuery