New Features Awaiting Implementation Interest

There are features that have been requested, but for which we are lacking implementor interest. Without two or more vendors interested in implementing the feature, they are unlikely to get added to the specs.

Feature	Interest indicated by...						Comments
	Mozilla (Firefox)	Opera	Microsoft (IE)	Apple (Safari)	Google (Chrome)	Others
Progress events on IMG elements	Jonas Sicking			Dean Jackson			Will likely be added soon
Cross-origin seamless iframes	Boris Zbarsky				Adam Barth		Will likely be added soon
Canvas: isPointInStroke	Jeff Muizelaar
Canvas: fillRule	Chris Jones
HTMLCanvasElement.printCallback API	Julian Viereck
Adding defer/async to inline scripts	Jonas Sicking
<meta name="referrer">					Adam Barth
A method to trigger autofill					Elliott Sprehn, Peter Kasting
Prerendering APIs					Gavin Peters
<template> (bug)					Rafael Weinstein
APIs for 'palpable' content (at the bottom)					Ojan Vofai
Some way to add files to <input type=file>					Nico Weber
Appcache: More detail in error events					Michael Nordman
The <menu> feature with many elements providing commands							Looking for feedback on new proposal
Appcache: Interceptor Worker							Needs use cases as well
FormData
Canvas: Stroke alignment
Canvas: control over when shadows paint
img@srcset: a mechanism to enable adaptive images
locale=""
video source material metrics (e.g. frame rate for fixed-frame-rate video data)
Exception object as fifth argument to onerror		zcorpan?
Cross-origin workers

See also: Who to ask about stuff