HTML5 is clearly the way to do web development today. Microsoft: The Web is better without plug-ins article tells that Microsoft began distancing itself from browser plug-ins last year starting with Internet Explorer on Windows 8′s Metro interface. Microsoft just said few days ago clearly: plug-ins are bad for the Web. Also Adobe is being reborn as a Web technology company that is advancing Web standards, not promoting its own in-house Flash technology. So it is not time to forget Adobe Flash and Silverlight for any new web service implementations.
HTML5 is still evolving standard and not in all parts ready. You need to know which parts are ready for use and which are not ready to be used. HTML5 Please web page gives help for web developers for using those new web technologies. HTML5 Please helps you decide which parts of HTML5 and CSS 3 to use. The recommendations for HTML5 and CSS 3 features are divided into three groups — “use”, “use with caution” and “avoid”. The result is a site that makes it easy to figure out which new elements are safe to use and which are still probably too new for mainstream work.