I attended An Event Apart 2011 in Boston and found a bunch of notes I never published. Here is the summary from Jeremy Keith’s presentation Understanding HTML5.
The presentation began with a Brief history of HyperText Markup Language (HTML) and Time Berners Lee work at CERN. HTML, first released in 1991, was based off of Standard Generalized Markup Lanuage (SGML). HTML 2.0 was released in 1995 by the IETF, HTML 3.2 in 1997 by the W3C, HTML 4.0 in 1997, and finally HTML 4.01 in 1999. Read more about the W3C.
HTML Didn’t do too much for the next 10 years but we were working in XHTML, XHTML1.0, and XHTML2.0. The W3c and WHATWG combined forces to make HTML5. Read more about the WHATWG. HTML5 is in final call for revisions, and it is estimated it will be a standard in 2021.
<!DOCTYPE html>
Why the new HTML5 doctype is so important. It assures us that HTML is backwards compatible, being able to render HTML ‘forever.’ It’s the bare minimum number of bytes for Internet Explorer to be able to render an HTML document. To quote @muqueca “<!DOCTYPE html> is a commitment to living web standards.”
Other simplifications
Character Encoding <meta charset=”utf-8″>
CSS <link rel=”stylesheet” href=”file.css”>
Javascript <script src=”file.js”></script>
The syntax for HTML5 is lax, uppercase, lowercase, and missing a few ending tags but will still render a valid HTML5 webpage. I know I will be using the XHTML strict syntax.
Deprecated (it’s been deprecated to use deprecate) Obsolete elements, (or sunsetted if you are Yahoo) include: <font>, <big>, <center>, <frame>, <noframe>, <acronym>, and more. See the W3C’s list of obsolete elements. Others have been updated such as the <a> element that can now, validly, wrap around an entire element so long as there is no interactive content inside of it. Some redefined elements are <b> and <i> which are now used to separate the content without extra importance., <hr>, <small> and <cite>.
HTML5 redefines the kind of content into document meta data, txt-level semantics, grouping content, embedding content, interactive elements, and sections.
New Elements (along with their specification definitions) include:
<header>
“a group of introductory of navigation aids”
</header>
<nav>
…a section of a page that links to other pages or to parts within the page: a section with navigation links.
</nav>
<section>
…a thematic section grouping of content, typically with a heading.
</section>
<article>
…a component of a page that consists of a self contained composition in a document, page, application, or site and that is intended to be independently distributable or reusable, e.g. in syndication
</article>
<aside>
…represents a section of a page that consists of content that is tangentially related to the content around it, and which could be considered separate from that content.
</aside>
<hgroup>
…used to group a set of h1-h6 elements when the heading has multiple levels, such as subheadings, alternative titles, or taglines
</hgroup>
<footer>
…typicall contains information about its section such as who wrote it, links related to documents such as who wrote it, linkes to related documents, copyright data and the like.
</footer>
Input Types
<input type=”…”>
if a browser doesn’t support this is defaults to a text box. Some of the types are search, tel, email, url, datetime, number, range, and color. More input types.
Posted by Ashley Baker 
