Web Forms 2.0, originally called XForms Basic, was the first step towards HTML5 — see html5.org. It provides a set of simple extensions to HTML4 and XHTML1 that simplify validation of user data on the client side for Web authors. It also introduced new control types, such as <input type=date>:
Roughly five years after the first official draft, posted on a W3C Member-only list, Web Forms 2.0 has been integrated into HTML5. This site serves a mostly historical purpose therefore.