HTML5 New Attributes

There are several new global attributes introduced by HTML5:

The contenteditable attribute indicates that the element is an editable area. The user can change the contents of the element and manipulate the markup.
The contextmenu attribute can be used to point to a context menu provided by the author.
The data-* collection of author-defined attributes. Authors can define any attribute they want as long as they prefix it with data- to avoid clashes with future versions of HTML.
The draggable and dropzone attributes can be used together with the new drag & drop API.
The hidden attribute indicates that an element is not yet, or is no longer, relevant.
The role and aria-* collection attributes which can be used to instruct assistive technology.
The spellcheck attribute allows for hinting whether content can be checked for spelling or not.