The World Wide Web’s markup language has always been HTML. HTML was primarily designed as a language for semantically describing scientific documents, although its general design and adaptations over the years have enabled it to be used to describe a number of other types of documents.
The main area that has not been adequately addressed by HTML is a vague subject referred to as Web Applications. The HTML5 specification attempts to rectify this (at last!).
It is still early days for HTML5 and CSS3 but browsers are supporting most of these languages already. Some of the effects you can produce with these will be genuinely stunning and usually without giving your developer a brain hemorrhage while trying to work out how to make it happen. If you need a new site design in HTML5 and CSS3, or just some advice on how your current site can benefit then I would love to hear from you.
Below is an example of the HTML5 “badge” indicating a page is built with HTML5 and some of its extensions.