Basically we are here to embrace HTML5 but this is neither a place that collects a bunch of sites that claimed to be HTML5 site nor a site starts with telling you how to "hello world" a html5 site. What we are doing here is to utilize some of HTML5 new features in real applications that can never be done in HTML4 era.

Precisely speaking, we focus more on <canvas> element. In HTML4 era, we can implement a web application pretty much like an stand-alone application. The stand-alone application runs locally with data accessing locally (well, sometime remotely). It will maximize the usage of local resouces (CPU,RAM,Storage etc). But with today's faster internet connection, if you treat your web server just as a logical drive on your local system with data accessing using Ajax, it's pretty much the same structure as standalone application. But you do distribute some computing onto another system, the powerful server, to relief your local system somehow. However, there is one aspect that the browser can not do or at least with difficault to do, that is graphics/image processing. To display a static image using <img> element in a web page is nothing more than a picture viewer.

The problem is we need more than that: we need the ability to scale an image or just part of an image. We need the ability to rotate an image in any angle. We need a combined transform operation onto an image: translate, scale and rotate. We need draw vector gracphics like CAD applications. We need process raster graphics in pixel level like Photo Processing applications.

<canvas> element allows directly render graphics and images to the web page. It's pretty much the same concept from Java Graphics2D. This feature will definitely lead web development to the so-called next web generation, especialy graphic based applications. If you ever developed or tried to develop graphic-based web application, you will most likely have to choose Java Applet, Flash, or ActiveX control to accomplish the task. However, it's really painful when you have to consider security, compatibility and even performance issues. What if user disabled the java applet? What if user doesn't allow downloading your ActiveX? A lot of what-ifs you would have to address in your code. Some people try to use javascript to manipulate DOM element to mimic a drawing environment, like using one-pixel size <div> element to mimic a point, but the performance will definetely be a headache issue.